Heat pump experts – moving water cylinder?

Getting ready to ditch the oil boiler for a heat pump now that permitted development rules have changed. The assessors (two separate companies) have both said that the replacement hot water cylinder can’t go in the existing airing cupboard as there isn’t space due to the sloping eaves. They’ve suggested either moving a stud wall about 2ft, or putting it in the garage and accepting the long pipe run to the second floor and out again to the existing hot water system.

Not convinced by this, as it’ll take three working days to get hot water at any of the taps, especially as it’s not particularly quick at the moment and I have no idea where the 22mm hot water pipes go after leaving the tank. Assuming it’s a relatively straightforward job to move a stud wall compared to the downsides of the cylinder in the garage?

There are some assessors here who have a lot more experience than me – does this reasoning make sense? The only other reason I could think of for moving the cylinder to the garage is that the pump is now attached to the cylinder and might be audible if in a cupboard off the bedroom.

Similar position. We had ours installed in June and we added a much larger tank (215ltr as oppose to about 100ltr previously) We only really had the option of putting it in the garage and as you say there is a delay for the hot water to come through. We had little choice and after a few times you just build in the fact that you have to add a few seconds before getting into the shower.

We have a slightly different issue but related to pump noise. The garage is below our bedroom so the very small and almost silent pump (when you stand near it) seems to resonate through our bedroom and obvs any small noise during the night is amplified. Any tips on resolving this would be appreciated. Ironically we have the radiator in our bedroom turned permanently off as I hate to be too warm overnight.

Get some vibration isolation mounts, you can afford to go quite soft on them and have the pump mounted on them instead of directly to the board that’s obviously resonating.

WRT the water run, yeah it’s a bit crap, ours is in the loft but it’s only a few seconds – we had a pressurised HWC put in so the flow is now great.

Regarding the run time for the hot water, my mate has put in a very well insulated loop, with a small pump that continually circulates the hot water round it and back to the tank, so that there’s only a very short run when he tuns the tap on.

what Greybeard said, with the addition of a timer so you dont have the pump running constantly.  you’ll only need a 15mm retrurn pipe back to the cylinder and a pump on very low speed – its only there to keep a trickle of flow going so that there is hot water in the pipe all the way to furthest outlet.

or accept the extra time/waste of water and live with it.

Assuming it’s a relatively straightforward job to move a stud wall compared to the downsides of the cylinder in the garage?

Yeah, sod that!!  It’s straightforward to move the stud wall but will create some mess for a while, will cost a bit and, obvs, you’d lose 2′ from a room!  No thanks.

Regarding the run time for the hot water, my mate has put in a very well insulated loop, with a small pump that continually circulates the hot water round it and back to the tank, so that there’s only a very short run when he tuns the tap on

Is it easy enough to install a new circuit though (carpets up, floor up, etc)?

Our HWC is at the other end of the house from our en-suite and it takes about 20-30 seconds for the shower to warm up which is a bit of a pest. I had the option to install a hot water circuit but I couldn’t accept the expense associated with it – that was 20 years now and I’m fairly happy with my choice.

Move the stud wall and keep the tank in the main thermal envelope. You’ll have less losses from the tank and the pipe run, and better response time for HW.

Well the response time will obviously depend on where the garage is in relation to the kitchen etc.

Although it takes 20-30 seconds for hot water to get to our en-suite it’s only a minor issue for our shower (bath doesn’t matter as you need cold anyway), it only takes a couple of seconds to get to the other bathrooms, kitchen and utility.

OP states a long run in their post.

Get some vibration isolation mounts, you can afford to go quite soft on them and have the pump mounted on them instead of directly to the board that’s obviously resonating.

Unfortunately its not mounted on a board but suspended in the pipe run. Pipe run insulated and fixed to the wall.

OP states a long run in their post.

… to the second floor though.  It all depends on the house layout and size.

Losing 2′ in a room could be painful or not depending on the size of that room and what could be done with the space being vacated by the current HWC.  The cheaper option (and better for installation, service, etc) would probs be to relocate to the garage but which is best is hard to tell and neither is ideal.

Unfortunately its not mounted on a board but suspended in the pipe run.

What pump is this for?

What pump is this for?

For pumping the water around the radiators

I’d move a stud wall, probably less hassle than ripping everything up to run new plumbing.

Custom cylinder? Vague recollection Newark cylinders offer that service

Thank you for the advice! I’m also quite twitchy about noise from circulation pumps having experienced a similar resonance in the past, so increasingly going off the idea of having it in a cupboard off the bedroom.

Also I gain four square metres of usable space instead of losing two, so that’s another advantage.

Feel sorry for whoever has to get an extra pipe down to the garage for hot water, but if they can find the loop somewhere else in the house that might actually make it easier as there’s a bathroom directly over the garage.

Question makes me wonder whether a large HW tank always makes sense. Presumably another option is an electric shower and something smaller per required tap? A heat pump keeping 200l of water at 60deg seems suboptimal but I suppose it depends on what the usage is.

I put my tank in the garage. No regrets.

I picked up the pipe under the floor making sure no doglegs left and added a return.

Fitted a circulation pump.

Minimal wait time.

Presumably another option is an electric shower and something smaller per required tap?

Already on the absolute limit for electrical supply so an electric shower is a no-go unfortunately.

Thinking about the time it takes to get hot water to the shower makes me think that picking up the hotel water pipe elsewhere in the house is not a bad idea.

It’s Octopus handling it, they’ve been pretty good but will need a new survey before they can generate a new plan. The surveyor has been really good, actually, and it was his idea to put it in the garage in the first place which I foolishly vetoed.

As science officer says you are much better off keeping the tank and pipework within the thermal envelope where the losses will be lower and will also help keep your house warm