[Closed] Bummocks, Condemned Boiler. I have questions. . .

Get thee to Boxt.co.uk, thou shalt be toasty by Thursday teatime.

Forget the boiler. Put a dynamo on your bike and put the bike in front of the TV. The pedalling will keep you warm and the dynamo can power everything else.

@136stu That's not going to work as I'm responsible for coffee and cake production at home, both of which are required to power my bike(s).

Do you have room for a pellet boiler and feed hopper?
I'm not recommending then, just wondering ('cos they're big and require a lot of space)!

The 30 year old condensing boiler has just been serviced and condemned as unsafe.

Maybe get a 2nd opinion? BG Engineers were condeming perfectly servicable boilers in their 1000s as they got a commission if you bought a new one from them.

I'm sure all the other options would be great for different reasons, but they sound quite time consuming to organise and install. Not something to really do as a stress purchase.

Second boxt. New one installed within a few days a couple of years ago. Best the local firm we had used for years could do was 2 weeks (in January when we had a small child).

What does "condemmed as unsafe" actually mean?

Sounds like "ohh, we can stiff you for a couple of grand to replace a perfectly good boiler with a new one" to me......

What does “condemmed as unsafe” actually mean?

Probably a leak from the combustion chamber or similar. As it's 30yrs old parts are probably no longer available. Though if it's 30yrs it's probably not a condensing boiler either.

As it’s 30yrs old parts are probably no longer available.

I can still get all the parts for our 30 year old boiler inc all the seals necessary to stop any leaks....

Edit I believe the gas solenoid valve isn't available new, but I could probably get one from a scrap yard.

Ours also has a slight leak in a weld by the drain tap in the back of the chamber, which drips rusty water down the wall occasionally. One too many flushes with DS-40 acid to clear out all the limescale (very hard water region).

Our first condensing boiler was over 30 years ago. Now got a Worcester Greenstar i, made in Clay Cross! Five year guarantee if serviced every year and it is very efficient with good hot water flow and quick heating start up.

Boiler condemned as combustion chamber leaks and combustion is incomplete lots of CO output through the flue. The necessary seal is no longer available (we had the last blower unit in Eastern England 2 years ago). It's an Ideal boiler which had to have new parts in the first year as they had a design fault that caused problems with combustion residue fouling the auto-pilot light. It doesn't owe us owt and newer ones will be more efficient and hopefully more reliable out of the box.

BG not involved in the servicing at all. They fitted it originally and I'm aware that they're sharks. This was a recommended gas-safe chap who won't be involved in the new supply/fit (no time until next year for that job).

Yes it is a condensor about 1996 vintage though and cost a fortune as it was new tech then.

I can still get all the parts for our 30 year old boiler inc all the seals necessary to stop any leaks….

The way gas prices are going it might be time to replace, or are you holding out for grants for non hydrogen compatible boiler replacements?

Mine is on the way out, parts not available, the circuit board that was replaced 12 months ago is getting stripped and flogged on eBay.

Thanks for the Boxt recommendations. I'm currently awaiting fun & finance control review of the proposals

. It’s an Ideal boiler which had to have new parts in the first year as they had a design fault that caused problems with combustion residue fouling the auto-pilot light.

Oh we had one of those piles of crap too. After having almost all it's innards replaced several times in the first 2 years it actually lasted about 20 years.

Ours hasn't been condemned, however it's been mended so many times now that we will have to get some other way of heating the house soon.
All other options seem really expensive eg. ground source heat pump, air source heat pump, wood pellets boiler. Not sure if we could get solar panels and go all electric.
Hoping that the more people that step away from gas heating, the cheaper the alternatives will become.
Trying to be environmentally friendly when heating a home isn't easy. We have a woodburner, but I'm loath to use it as every other person in our area has one now and the pollution in our area is noticeable.

I have no useful suggestions to make but I am determined to make bummocks a much more widely used expression of mild annoyance...

Anyone know anything about water source heat pumps? I've got riparian rights on a small tributary of the Irwell and an old house so airsource not enough and the back garden isn't huge.

@sandwich - do you have the boiler GC number? I have some contacts in the gas spares industry, I can see if they can track a seal down for you

Thanks @northernmatt but it's been faulty for a little while and there's a fair amount of corrosion inside it. I suspect the brand new blower unit has broken things down with its better pressure. The recommended chap was pretty good as he did have a thorough check around for bits before he said it was dead. I was also sent a pic of the CO readings outside (>500).

F&FC have told me to buy a new pack from Boxt. Fitting is at the end of the month. Day off tomorrow to fit a time-switch to the immersion heater and a bit of a bike ride (with mud) to get over the money spent.

I can still get all the parts for our 30 year old boiler inc all the seals necessary to stop any leaks….

The way gas prices are going it might be time to replace, or are you holding out for grants for non hydrogen compatible boiler replacements?

It's probably not the most efficient (75% IIRC vs 90 something for a brand new one), but that 20% on our gas bill (£600 / year) would give a payback of 10+ years to break even on the cost of a new one.

I just figure I'll keep it going as long as a I can as that's probably the most environmentally friendly thing to do (a new boiler etc has a lot of CO2 baked into its construction etc).

Well it's the job that keeps on giving. Timeswitch requires new wiring as idiot original electrician wired both the immersion and the boiler controls onto a 16A radial.
Bits ordered from CEF (MCB and pattress boxes) and a day of cables and rewiring is in store! That leaves one spare way in the consumer unit and an electric car will use that for charging in the near future.

I came across this last month whilst idly thinking of a new boiler - not having bought a boiler in the last 10 years I hadn't come across BOXT. That lead me to Heatable which operate on a very similar model. 5 mins answering some questions, 2 or 3 boilers recommended, picked one and booked in for 2 days later. Have to say it was thoroughly pleasant experience - dead easy to book, local guys arrived on time, complete boiler switch out, clean out of system, new mag filter fitted etc. and re-commissioning - done by 3pm and it's been perfect since. Heatable were also about £800 cheaper than BOXT for the same boiler. Just for comparison, for a new Worcester Bosch combi for a 5 bed/3 bathroom house it was £2350 (inc. a random £100 discount code I found online.) So... in short, if you need a new boiler - Heatable are definitely recommended.

Hoping that the more people that step away from gas heating, the cheaper the alternatives will become.

Problem with ground/air source heat pumps isn't the pump cost, but the cost of sufficiently insulating the home, plus upgrading rads and/or putting in under floor heating. My solid wall Victorian house would cost crazy money to get the insulation done properly and costs will only increase with popularity as it's a labour and supply intensive job.

A heat pump install would be a major job for me. All ground floors would have to come up for insulation to be fitted (wood over a void). Then finding room for the larger radiators and the associated pump. I expect that it will be an easier job when the newly fitted gas boiler expires in around 20 years.

Insulation upgrades are not needed in a lot of ASHP installs, however that is with current RHI funding, it will be different when the new scheme comes up although think the vouchers will be snapped up very quickly

Just found this thread as our boiler is giving me the willies. It's not dead yet but our radiators never fully heat up and the tap water isn't as hot as it was.

We live in a street of 12 year old houses and loads of people have already replaced their boiler. I'd rather not have to do it in an emergency, in the middle of January, with a screaming baby under one arm.

4 story house with a big water tank on the second floor, boiler on the ground floor. Constant steam blasting outside so does that mean none condensing?

No idea where to start choosing a replacement.

EDIT: update- tap water is now freezing, showers are freezing. Radiators are only warm at the top. I've switched on the immersion heat on the tank. Xmas money is about to go down the drain.

It’s not dead yet but our radiators never fully heat up and the tap water isn’t as hot as it was.

Might just be the pump or a solenoid valve is on the way out, rather than needing a new boiler...

We get through a CH pump every few years, must be on our 4th or 5th now (same boiler). Often giving it a whack with a screwdriver will get it spinning again when it's on the way out, so buys a few more days before it refuses to turn at all.

Insulation upgrades are not needed in a lot of ASHP installs, however that is with current RHI funding, it will be different when the new scheme comes up although think the vouchers will be snapped up very quickly

Do you mean the insulation upgrades are not needed to get the funding or not needed to keep the house warm in winter?

Genuine Q as we're in a drafty, solid walled Victorian house with voids under the floors etc, so we leak heat all over the place.

Radiators are only warm at the top.

That's not a boiler fault. The system's full of shit silt, needs flushing.

Might just be the pump or a solenoid valve is on the way out, rather than needing a new boiler…

That’s not a boiler fault. The system’s full of shit silt, needs flushing.

You might be right. The boiler sounds like it's firing up and working as normal. The pump sounds like it's doing something but when you move the power switch between levels 1,2 and 3 it cuts in and out and takes a while to come back.

It fitting a new pump a DIY job? It's just sitting right there, easy access.

I've bled all the radiators but where do you start draining the system? Is there a big filter or sump somewhere?

We've got heat and water now with the immersion heater but it'll be costing a small fortune to run.

It fitting a new pump a DIY job? It’s just sitting right there, easy access.

Yep, very basic plumbing, you just needs a large adjustable spanner and some towels. You don't even need to drain the system as the pump should be installed with shut off valves immediately above and below it. NB You will have to wire the new pump in, but that is also very simple.

I’ve bled all the radiators but where do you start draining the system? Is there a big filter or sump somewhere?

If there is silt in the system it will be sat in the bottom of the radiators, so draining the system won't shift it. Most modern systems have a magnetic filter installed which slowly attracts the muck and you then clean it out every so often (every few years in our case). I added one to our 30+ year old system a few years back.

The problem you have sounds like the pump isn't working properly, not circulating enough hot water to get the rads properly hot; or, less likely, a solenoid valve is only part opening (they normally just fail and don't open at all).

Thanks for the tips as always chaps! I feel almost optimistic.

Considering the price of pumps and the fact it's probably never been touched or replaced I don't mind fitting a new one. With any luck we'll get some hot radiators on the top floor for the first time.

I just need to find a replacement for this...

I have Screwfix and Tool Station 5 minutes away. This could be sorted tomorrow if I pull my finger out.

Could be the 3 way diverting valve shark attack. Cpuld be gummed up rads if bled thoroughly and still cold spots.
Drain off valve is a swaged 15mm jobbie with a square 8mm top, usual outside or on a low rad near the boiler.if the boiler fires up ok then it cpuld be tje pump, or its full of crap

Can you drain some ch fluid intp a jam jar and add some wire wool or steel nails. Use the bleed off on the top of a rad. If they rust then you jave been running the system with insufficient inhibitors. So you need a power flush and magnetic trap fitted. Might not be too expensive maybe £250 or less if your not dpwn south

Yep, tjat looks straightforward enough.
Adj spanner on the valves top and bottom, if you don't have the handles. old towel and big adjustable on the pump flanges.
Maybe crack the front nut to depressorise the pump first.
Pick up sentinel x100 when your there as well.
That munsen ring mount looks a little worrying, i guess its an aesthetic cover amd not a water tight jacket

Right, I've now got a jam jar full of radiator water and wire wool! So we'll see how that goes.

Just had a thought though, I know our radiators are patchy but we've got heat now with the immersion heater. With just the boiler we had nothing. The boiler might still be borked. Christmas might still be cancelled.

Grundfoss pump from Scrwfix. just check the head (Mtrs) if your pumping up 3 floors.
So your 3kw elec immersion heats the water tank and then the idirect ch fluid rund through that and heats up? which then evenly heats the rads ? abit slowly but it does something ?
stuck diverter valve usually has a go -no go feedback wire if its not moved into the correct postion , but you boiler stills fires which does sound like pump but ianap. Bear is , he knows more than me , i just sell the bits and bobs

Just had a thought though, I know our radiators are patchy but we’ve got heat now with the immersion heater.

You shouldn't get any heat in the radiators from the immersion, the systems are isolated (almost). The HW the boiler heats goes through a coil inside the HW tank and then goes back to the boiler. The water in the HW tank you use for baths never sees the boiler and is heated indirectly in the HW tank.

or do you just mean you have hot water now?

I did not know that, thanks.

We definitely have heating and water at the minute. The radiators came on when the timer kicked in but they didn't get hot from top to bottom. This morning when we had just the boiler on it sounded like it was working but we had nothing.

I'm at work all day tomorrow, I'll turn off the immersion and have the Mrs put just the boiler on and see what happens.

That munsen ring mount looks a little worrying, i guess its an aesthetic cover amd not a water tight jacket

I saw that and thought WTF!

I saw that and thought WTF!

If the tank construction is anything like my Megaflo's then the outer shell is just there to hold the insulation around the inner pressure vessel (water tank)

Our turn now, woke up to no HW!

The HW motorised valve motor has died, lukcily the manual over-ride is fine, so just delayed showers (currently waiting for it to heat up).

Must be the 3rd or 4th motor I've replaced since buying the place. Funny thing is the CH one is original to me, so over 20 years old. Although, thinking about it, for most of the year it doesn't do anything, whereas the HW motor comes on every day.

We also woke up to no hot water since we switched the immersion heater off yesterday morning. Radiators are still working though. I've started contacting plumbers, I want it sorting out rather than guessing.

I've checked out Boxt and Heatable. Yes it looks easy but it's hard to swallow over a 2.5k hit at the minute. It's nearly 3k if you add on a pump and a couple of valves. I might just close my eyes an click the button so I can stop stressing about it.

We also woke up to no hot water since we switched the immersion heater off yesterday morning. Radiators are still working though. I’ve started contacting plumbers, I want it sorting out rather than guessing.

If your radiators work then the boiler is fine. It's probably just the motorised valve which isn't opening the HW circuit. They have a lever on them you can use to manually over ride. A new valve is about £70, a new motor for a valve is about £20 (if you can find the right one).

See 1:12 into this for how to over ride

I think our boiler is the original from when the house was built in 1972...... Is that a STW record

I realise that is the equivalent of taking off my mudguards.....

I think our boiler is the original from when the house was built in 1972…… Is that a STW record

Getting there, ours is over 30 years old: "Potterton Nettaheat Electonic". The fact it has 'Electronic' in it's name tells you that was cutting edge stuff when they first sold it! It even has 'Electronic' written on it in Space 1999 font!

A quick google suggests 1988 onwards...

If your radiators work then the boiler is fine. It’s probably just the motorised valve which isn’t opening the HW circuit. They have a lever on them you can use to manually over ride. A new valve is about £70, a new motor for a valve is about £20 (if you can find the right one).

Thanks for that. We've just had a plumber in our office to fix our heating and he said the same thing. So I've phoned home with some instructions to open the valve manually. If that fixes if I'll replace the valve.

So I’ve phoned home with some instructions to open the valve manually.

So there are two different set ups.

We have the pipe split after the pump and two motorised valves in parallel, one does CH and one goes to the HW tank, so in our case you pull the lever on the HW tank motor to get HW.

The other set up is all in one with a three way switch (I think) where it can switch on either CH or HW (or maybe both). Never played with one, so not sure how the lever works on those. Someone else on here will know....

Thanks to all the tips I've tracked our problem down to this thing...

When I tried it the other day and when the Mrs checked it today the lever was just flapping around. Tonight when the timer is on and the radiators are roasting but we had no hot water I turned it to manual, felt the resistance and could hear it opening up. Five minutes later, hot tap water. But also full blast heating regardless of where I set the thermostat. So it's all or nothing at the minute.

So not fixed yet but very relieved to know the source of the problem.

When I tried it the other day and when the Mrs checked it today the lever was just flapping around.

OK, when the motor has turned the valve on, the lever goes loose like this. This is normal.

When the motor is off the lever has to overcome a spring to open the valve and normally makes a winding noise as you push it across.

Five minutes later, hot tap water. But also full blast heating regardless of where I set the thermostat. So it’s all or nothing at the minute.

Would need to see a diagram of how your system is plumbed, as in what connects to the output of that valve....

So this is ours (as an example):

The pump pumps downwards and the pipe splits two ways after the pump - water paths shown by red lines. The white box (with black 'X') is the HW motorised valve which controls access to the heating coil in the HW tank. The CH motorised valve (silver box with white 'X') controls access to the CH pipes which dissapear under the floorboards.

With this set up the CH and HW circuits have separate switches. However, when I first bought the house the HW switch was missing and HW was heated whenever the boiler was on. I added it later. Your system might be like this, HW on all the time with the boiler and CH being switched.

[url= https://live.staticflickr.com/65535/51715750896_d9099952ab.jp g" target="_blank">https://live.staticflickr.com/65535/51715750896_d9099952ab.jp g"/> [/img][/url][url= https://flic.kr/p/2mMWJZw ]CH plumbing[/url] by [url= https://www.flickr.com/photos/brf/ ]Ben Freeman[/url], on Flickr

This is what we have. I freely admit I have no idea how it all works...

This is the little lever that wasn't doing anything but I imagine it wasn't 'activated' when I first checked. Last night when we had toasty radiators but no hot water, I pushed it from Auto to Man and heard something kick in.

The gave us hot water but also I think I realised that our radiators are on separate circuits. The ones in the rooms have the adjustable valves on and go on and off with the timer no problem. The radiators in the passage and stairwell don't have the adjustable valve they're just one or off. These are the ones that were blazing last night after I moved that switch. I didn't even know our house could get that hot. I had to switch off the boiler itself to cool it down.

Is this another valve which unleashes something else?

Unfortunately, I've had to come to work again and leave Mrs and baby at home with no hot water and we still can't get a response from any plumbers.

The motorised valve in the bottom picture looks like the one that heats your hot water tank (as it's in that circuit). That's the one you want to manually open to see if that fixes your hot water issue - if it does then it's that valve that's at fault (also check that it's getting power when the hot water is supposed to be being heated).
The valve in your first picture looks like it controls the central heating (but I can't see where the pipe coming out if it is heading). By pushing it to manual you overrode the thermostat so the boiler just kept going and the rads without TRVs kept putting out heat - the ones with TRVs shut down because they'd reached the room temp hat they're set for.
So move that valve back to manual [do this anyway/now] and manually open the lower valve.

I also see what looks like a water thermostat on the cylinder - check what temp thats set for. That could also be a failure point - if it's broken it might stop the valve opening for the hot water.

Oh and I'd be checking the control box with a meter also as a bad connection in there would stop power to a motorised valve or the hot water thermostat.

The main thing is that your boiler is absolutely fine, you just need to find out what's stopping water going from the boiler to the HW tank.
So there's a few things to check but they're not difficult - but move that CH valve back to Auto first.

The trvs will lower the flow rates or shut off the rads where they are fitted. Your hall ones on open loop just fun on f s a. Turn down the stat if they are red hot.
Looking at your photos looks like 1 pump, 2 x solenoid valves plus filling loop, drain valve, 2 or 3 prv for safety.
Dumb q is this gas of just electricity. I can see the tail of the immersion in the piccy but no gas train.
The boiler works if the rads get hot throughout which is great. What you have is a control issue.
Hot water from the boiler goes up stairs to a coil inside a cylinder and back again via the pump.
Hot ch fluid goes round the rads pushed by the same pump.
To allow hot water to be produced without heating the house a valve lets the hot ch fluid go up to the hw tank via a valve and the pump.
In winter another valve opens and lets hot ch fluid circulate round the rads in a out and back loop. This is controlled by the lower lhs valve i think.
It will be the highest rhs valve that lets ch fluid recirc through the hw cylinder, indirect heating system. Hopefully its just this thats stuck shut or broken. Iirc the tops come off and you can manually operate them, or slide lever operates the valve.

These are not expensive and ypu can switch the motorised valve yourself

It will be the highest rhs valve that lets ch fluid recirc through the hw cylinder, indirect heating system.

Why?
If you look in the picture it's the lower motorised valve that's in the HW heating circuit and the upper one doesn't seem to be related to the HW circuit as all.
Could be wrong obvs.

I think you correct. A closer look reveals the ch drain down point under the solenoid, however that could also enable drainage of the indirect loop.
From that pic its impossible to tell
We pretty much typed the same thing
Easy way to tell. Hold pipe up stream of valve. The one that doesn't burn your hand is busted

From that pic its impossible to tell

It looks like the pipe coming out of the [bottom of] the lower motorised valve goes straight into the tank - in which case that valve is controlling the HW.

The one that doesn’t burn your hand is busted

As I said, the valve might be fine, the issue might be power getting to it or the HW thermostat saying that the water hot when it's not (i.e. it's bust!).
The first thing to discover is whether the valve will open manually and if this fixes the issue. If it does then why isn't it opening automatically? - either the valve is bust or there's an 'electrical' issue (which could just be a connection)

So move that valve back to manual [do this anyway/now] and manually open the lower valve.

A quick check of my post and this is wrong as it should read "move that valve back to Auto..."
(I did word it correctly further down the post though!)

I had that setup at my old house.

The micro switches that signal to the boiler and pump to start when the valve is open are notoriously unreliable on Danfoss valves.

It’s a 15 minute job to change the valve head but because the valves and cylinder are supplied to the house builder as a complete kit you’ll have to connect it to the wiring centre yourself (note the coloured connectors which are fitted at the factory).

Open wiring centre, take photo of existing layout and then connect in the new valve head. It’s all colour coded.

This is what we have. I freely admit I have no idea how it all works…

Looking at the plumbing I'm not surprised, seems to unnecessarily complicated...

Thermal store.

🙂

Read through some of this and having had a recent thread on boiler woes, I'll throw my tuppence in ...

Our boiler stopped working, coinciding just after a boiler service. That service engineer didn't chose to come back. Phoned another boiler chap, he wasn't sure but thought maybe silt in the pipes stopping water flow, but went away having 'cleared' part of a pipe and the boiler still didn't work (he blamed the lack of gravity not being able to pull water down). Third plumber convinced the boiler was on its last legs so start with the pcb, and then work through each part of the boiler replacing it.

Through lots of good help on here, it boiled(!) down to a:

1. motorised HW valve stuck open - simple fix
2. some silt in the pipe just before the circulating pump - cut it out and replaced (and replaced pump at the same time as it's v old)
3. condensor trap blocked
4. condensor piping (which has severla 90degree bends) blocked

Now it's purring away.

And none of the plumbers suggested these things. And our boiler is v old, so there's hope!

I managed to get a reply from an actual plumber today. He asked what the problem was, I sent him the pictures and he said he'd get back to me with a price and a date. This was at 1pm and I've heard nothing since.

The Danfoss thing is back on auto. I can't see how to switch the bottom one to manual. It's not obvious and I haven't crawled into the cupboard for a look. I might have a look when mini me is finished screaming himself to sleep. My head is pretty battered by this time on an evening now.

He asked what the problem was, I sent him the pictures and he said he’d get back to me with a price and a date. This was at 1pm and I’ve heard nothing since.

I imagine the run up to Xmas with the temp dropping and everyone switching CH on means plumbers are pretty busy. Plus stuff like this are low value jobs with all the same faff of visiting, quoting, getting parts etc.

I can’t see how to switch the bottom one to manual.

Probably doesn't have a "manual" setting I've never seen that before but I'm not a plumber).... Just move the black lever over to the other side - this is what would happen when the motor does it.

The gave us hot water but also I think I realised that our radiators are on separate circuits. The ones in the rooms have the adjustable valves on and go on and off with the timer no problem. The radiators in the passage and stairwell don’t have the adjustable valve they’re just one or off.

Could just mean no one bothered to put TRVs on them. I didn't bother in the bathroom, for example, as we'd always want that one on to dry towels etc.

Probably less likely that you have radiators on different circuits, but not impossible.

These are the ones that were blazing last night after I moved that switch. I didn’t even know our house could get that hot. I had to switch off the boiler itself to cool it down.

Well the mechanical over ride switch over rides everything inc thermostats etc, so the boiler just keeps going and only its internal water temp sensor (probably set about 70C) is holding it back. So it will keep heating the HW / radiators for ever - which, unless it's sub zero outside, will get the house pretty toasty.

NB The boiler will have been designed to run like this, so I doubt it has really 'over heated', it's just you've not seen it that warm before. Older boilers don't have much insulation, so act as a mini-radiator.

Whilst you're using the manual over ride, you could turn the boiler temperature down a bit, normally a dial on the boiler control panel. Sometimes its marked in degrees C, ours is just - / +, so just trial and error.

I contacted SIX plumbers today. The sixth one has just left. He said he could come right away or I can wait two weeks.

Two new motorised valve things (which look a lot more robust than the old plastic ones) fitted for £165. It now appears to be working perfectly and I feel massively relieved.

As soon as he looked in the cupboard he spotted that the expansion tank was full of water. No idea how he did that. He said we need a new one as it's just pouring the excess water down the drain but that's a job for another day.

He also said we've got one of the most unreliable boilers ever made. But, it fired up and it's working fine for now.

Also, Doris and Mini-me are visiting family over a hundred miles away so I'm looking forward to a night of uninterrupted sleep and a couple of days without changing any nappies.

Two new motorised valve things (which look a lot more robust than the old plastic ones) fitted for £165. It now appears to be working perfectly and I feel massively relieved.

Pretty good value!

A bit of parts darts there!
The chances of both motorised valves being borked at the same time is very, very slim - and we know the CH one was fine as the radiators were working.
But hey..... You've got it sorted and hopefully learnt a bit about CH systems.

Yeah you're right but I honestly don't mind paying to have two new ones. I was expecting the bill to be in the multiple hundreds so it's not too bad.

I can sort of see why he changed both as whilst you drain the system etc, you may as well change both as that will buy another 5 ish years of working motors etc. Otherwise he could be back in 3 months to drain the system and swap out the other one.....

I can sort of see why he changed both

Yeah I’d do both whilst it was drained down. Not worth the time diagnosing which one. And if one’s gone end of life, other won’t be far off. Sensible approach.

Want to hear something funny?

Boiler is dead. It's gone completely silent and turning it off and again doesn't fire it up. No heating, no water, nowt.

This plumber did make a right song and dance about how crap my particular boiler is and how unreliable they are and sometimes when you switch them off they just don't come back on. But it's worked fine all this time. Then when he left he texted me a quote for a replacement.

Is it possible he put a hex on it? I did have to leave him alone while I went to a cash point. He could have done a magic dance or just stabbed it with a screwdriver or anything.

What a shitty week.

The boiler is either an Ideal Icos or Potterton Suprima I think is the model. Both truly awful but the icos wins it for me

Oh FFS!
Maybe there's air in the system that's caused the boiler to lock out?
Did he/have you bled the rads?
Did he actually drain right down to swap the motorised valves or just close the valves above them?
Is there power going to the boiler?

The boiler is either an Ideal Icos or Potterton Suprima I think is the model. Both truly awful but the icos wins it for me

We have an Ideal Icos.

I've just had him on the phone we're trying to troubleshoot it. It's past my bedtime.

Did he actually drain right down to swap the motorised valves or just close the valves above them?

He just said he didn't drain the system, just the pipes in front of the tank.