ASHP design and BUS eligibility

MWT

https://forums.moneysavingexpert.com/discussion/comment/81920234#Comment_81920234

You may need to be careful on the timing as you'll need the boiler to be removed before the BUS grant can be claimed, so make sure you are clear with your installer on what you will be paying and when…

greenbee

https://forums.moneysavingexpert.com/discussion/comment/81921759#Comment_81921759

I suspect the boiler will need to go some time before the heat pump goes in as we need to clear the space where the boiler is and build the plant room before installing anything. The whole project will be phased as there are renovations going on that will dictate e.g. when the underfloor heating is installed (as well as when the boiler comes out and heat pump goes in).

matt_drummer

i would check that if you want the BUS grant.

The eligibility wording says you must be replacing a fossil fuelled heating system.

If you take the oil boiler out and then install a heat pump some time later then you are not replacing but adding as you no longer have a heating system.

Check with your installer before taking your oil boiler out.

greenbee

I'll get the builder, the plumber and the electrician together in the next couple of weeks as there's a lot that needs planning - they must allow time to prep the boiler space for the heat pump - it's just that by the time it comes out, there won't be huge urgency to get the pump in, as the weather is likely to be warmer. Mind you, the heating will be off soon anyway as I'm almost out of oil… but the pump can't go in until the plant room is constructed (and the inverter and battery are going to have to be disconnected and moved for a bit at this point too, so half the house will have no power as it's on the backup circuit, so along with the dust it's going to be so much fun…)

Martyn1981

https://forums.moneysavingexpert.com/discussion/comment/81916605#Comment_81916605

I'm the same, always thought it odd, as it will slightly insulate the rad (unlike enamel) each time it's painted. Though the efficiency impact is probably small to negligible, and specialist paints are available. Going back to the 70's, I think it may have helped to reduce kids getting burned as water temps were so high. I remember in school, you could press a crayon on the rads, and liquid wax would run down. 😗

And now I get to remove the rads each time I decorate a room, which is weirdly pleasurable.

The_Dude_1955

Having had a Heat Pump fitted and now removed there are things I have discovered that were not forthcoming before I started the process. A heat pump will not produce a temperature above 55C compared with the 70C+ of a gas boiler. To compensate for this the radiators need enlarging and the feed pipes feed all need replacing with a smaller bore size. Your property EPC rating should be A or higher. The only good decision I made was to pay for my system with a credit card! Thank you ML. I should really have had better due dilligence on the installer as it turned out they were not licenced to installer and I lost the government payment. Think long and hard before you take this step

MWT

https://forums.moneysavingexpert.com/discussion/comment/81927505#Comment_81927505

So much wrong in this post..

Max flow temperature on my Vaillant heat-pump is 75C, but a correctly designed and sized system should not need to go that high.

You do not need an A rated EPC. just a properly sized system for your heat loss.

Some radiators may need to be changed, but not all (in my case it was 1 radiator).

You certainly do not need to replace all the 'feed pipes' with a smaller bore size, that would make no sense at all.

Get quotes from Heat Geek, or Octopus or other properly qualified installers and compare before proceeding.

greenbee

Thanks MWT!

I've already had one survey/design/quote from a properly qualified installer, and am getting another. I've also done my own research both here and elsewhere - and am being supported by a local heat pump owner who went to the effort of getting himself Heat Geek trained when he was researching his own installation (and now spends most of his time sorting out neighbours' set-ups!).

I've already upgraded quite a bit of pipework from 15mm to 22mm, significantly increased the size of emitters in most rooms, and am looking forward to unzoning the currently badly-designed setup as well as getting rid of the stinky oil boiler and the annoyingly small tank!

Martyn1981

I'm A2A not ASHP wet system, but I thought this vid from Everything Electric was excellent. It's actually a second visit, to a home that was very happy with their ASHP, but following comments from viewers, talks about how it could have been even better. Crucially the HP unit is too powerful. And having proudly said that the house was so warm a radiator was removed ….. folk also said, that that wasn't the best way to run it.

I thought this was a great reflection of the community on there, and mirroring the way folk on here try to help and advise.

Really worth a watch, or just a listen in the background (I was doing Sudoku puzzles).

Size Really Does Matter When It Comes to a Heat Pump!

Is your heat pump too big? We revisited Judith Leary Joyce’s Victorian home in St Albans (featured on the channel last year) after she discovered her heat pump was oversized AND she'd been running it all wrong! The Everything Electric community spotted the problem before she did! Here's what happened next.