Kitchen appliance warm feed from ASHP advice.

Do the appliances even have inlets for hot water? Mine don’t.

Edit: even if you plumbed hot water into the cold inlet it might mess the cycle up as I presume it’s expecting cold, mains pressure water and has been designed around that.

Very few appliances have a hot and cold feed these days. Not sure what a washing machine would do with 50c hot water hitting the appliance and I suspect some clothes that require low temps on the label would not fair well either. Dishwasher maybe but probably blow the warranty if you had any issues.

I was going to say, a lot of appliances heat the water onboard, so only need a cold feed.

If you are refittng the kitchen anyway, I'd keep it simple and just buy appliances that don't require a hot water feed.

EDIT: its not clear if you are buying new appliances or keeping the old ones.. if buying new, pay attention to the new EU energy ratings - an "A+++" is now rated "C" on the new scale, so look for "B" rated stuff or better?

For a washing machine, for example, they show at a glance the number of water liters per cycle, the duration of a cycle, and the energy consumption, as measured for a standardised programme.

https://ec.europa.eu/commission/presscorner/detail/en/ip_21_818

I was going to say, a lot of appliances heat the water onboard, so only need a cold feed.

Indeed. But I think the OP is asking if this is now the only way, and if using the warm feed from an ASHP with the right appliances might be more energy efficient.

Many years ago we accidentally fed hot (from Gas Combi boilers) into a cold only washing machine… and shrunk some lovely old Swobo kit.

I expect appliances with cold only feed and built in heat exchangers are the energy efficient future.

Wouldn't bother. A dishwasher uses 10 litres of water, so you're basically going to be filling it with room temperature water that's in the pipe anyway. It doesn't fill 10 litres at once, it does it in chunks so you're never going to see a benefit. Same with washing machines, they're pretty efficient these days.

I'd spend the money on a heat pump tumble dryer, where you will see noticeable savings.

I wouldn't do it a lot of machines use cold water as part of the cycle too.

If you have an ASHP then you are better off looking into your energy tariff and finding one such as Octopus Cosy that has cheap periods during the day and run the appliances during those times. Our kids are older so we try to minimise cooking during the very expensive time so it works for us well.

We have switched to a ASHP and utilise that tariff, our minimally insulated turn of the century flat is now so much more comfortable and also drier. But as part of it we switched to that tariff and we are roughly £2 per day cheaper at the moment than last year for a similar period. We also over heat our water during cheap periods. Our electricity cost averages out at 19p per kW at the moment.

And in the real world of actual experience.
I hot fill my dishwasher and washing machine from the combi boilers.
Dishwasher first. It's a 12ft run from the boiler so I run the hot kitchen tap to fill the feed pipe the dw spurs off with hot water and simultaneously start the machine. I think it takes about 6 ltr at this stage . Due to thermal dynamics it's tepid after the initial 10 mins rinse , I can then see the elements kicking in on the smart meter. Is it cheaper , yes but not by much , maybe 5p a cycle.
Washing machine lives under the combi so gets initial fill straight off what ever the initial cold water pressure firing up and the ramp up temp and then fast flow hot water is , minus heat loss in clothes and cold machine. I guess it's 30 to 40c .
If I'm on it I then switch off the boiler so the rinsed are cold feed only. This is a bigger saving and I think it's close to 10p a cycle , as the washing machine element never fires up.

As above -

Very few appliances have hot fill these days

Pipe losses can be signifiant

you can't connect a hot fill to a cold inlet because rinses don't need to be hot.

And in the real world of actual experience.
I hot fill my dishwasher and washing machine from the combi boilers.

How many times a week do you run the dishwasher and washing machine..... twice each?  That's an awful lot of hassle to save about £5/year!

(are you factoring in the appliance will heat the water with electricity compared to gas which is less efficient plus incurs losses between the boiler and the appliance?)

I hot fill my dishwasher and washing machine from the combi boilers.<br style="box-sizing: border-box; --tw-border-spacing-x: 0; --tw-border-spacing-y: 0; --tw-translate-x: 0; --tw-translate-y: 0; --tw-rotate: 0; --tw-skew-x: 0; --tw-skew-y: 0; --tw-scale-x: 1; --tw-scale-y: 1; --tw-scroll-snap-strictness: proximity; --tw-ring-offset-width: 0px; --tw-ring-offset-color: #fff; --tw-ring-color: rgb(59 130 246 / 0.5); --tw-ring-offset-shadow: 0 0 #0000; --tw-ring-shadow: 0 0 #0000; --tw-shadow: 0 0 #0000; --tw-shadow-colored: 0 0 #0000; color: #000000; font-family: Roboto, 'Helvetica Neue', Arial, 'Noto Sans', sans-serif, -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Apple Color Emoji', 'Segoe UI Emoji', 'Segoe UI Symbol', 'Noto Color Emoji'; background-color: #eeeeee;" />Dishwasher first. It’s a 12ft run from the boiler so I run the hot kitchen tap to fill the feed pipe the dw spurs off with hot water and simultaneously start the machine. I think it takes about 6 ltr at this stage .

did you read this back after you wrote it ....

it reminds me of the episode of bottom "we fill the kettle with cold water from the hot tap to reduce wear on the cold tap"