Hi All.

I am looking to have a heat pump and 250l cylinder installed in Somerset. I have had 2 heat loss calculations and two quotes. Both come to over 12k for a 4/5kw heat pump and cylinder system. The flow and return pipework is already in. UFH and manifold on the ground floor. I don't know how they can justify that cost but unless I can find an alternative I am going to have to go with it. I have already had the BUS voucher (which has expired but I am eligible). I have wasted 6 weeks while my useless plumber goes back and forth with the plumb centre and they are quoting to install a pre plumbed cylinder with a buffer tank. I absolutely don't want/need a buffer tank or zoning. I have had to take out a bridging loan to complete the build so every month wasted is costing a fortune so I am looking at all options, one of which is forgetting the BUS grant/MCS and just getting someone to get on with it, hence my question here. I am all ears if anyone can recommend an alternative course of action.

The heat loss for the house is 3.2 - 3.4kw. MVHR is installed. It is a 3 bed detached new build with UFH on each floor (the first floor is yet to be done but I have a design and think I will get the builder to do this.)

4kW Hiaer heat pump £2050 incl VAT from Wolseley (you may need to buy an indoor unit also now). You will 2x anti freeze valves an isolated valve and couple of flex hoses. Install direct to UFH manifold.

Buy a direct cylinder and just heat via immersion about £500. Any plumber can install your cylinder.

About £3k for parts plus labour to install.

Edited 23 hours ago23 hr by JohnMo

Not directly relevant or anything to do with us, but just to introduce Otter South West

When we moved here (South Somerset) in Oct '25 we inherited a Daikin ASHP which we decided we'd like serviced and they are one of the local approved co's...

But the point I wanted to make was that the guy Chris who came was professional, extremely knowledgeable, helpful and did a great job for us well beyond a service. If you need someone like that then you could ask them if they could help...

If I do some form of DIY install is there any issue with getting building regs sign off for a new build? That was my plumbers excuse. Is the BCO going to demand an MCS cert?

1 hour ago, jimseng said:

If I do some form of DIY install is there any issue with getting building regs sign off for a new build? That was my plumbers excuse. Is the BCO going to demand an MCS cert?

No issue if you comply with building regs! For a heating system you'll likely need a part P spark to sign off electrical work or ask and pay for BC to inspect it. If you're installing an unvented cylinder you'll need that signing off by a qualified plumber. No MCS cert needed but it would likely be accepted by BC as evidence of compliance with regs

Whether you can get tradesmen to sign off work they haven't done is a different matter!! BC are obligated to inspect electrical work that you've done but I don't know about pressurised cylinders.

Edited 10 hours ago10 hr by Dillsue

You may may need an MCS noise certificate, but zero reason not to do that yourself, MCS provide all the guidance. But don't provide it not specifically asked.

What does you planning permission actually ask for?

9 hours ago, JohnMo said:

What does you planning permission actually ask for?

I don't think there is anything particular in the planning consent, just a heat pump location specified by the architects and to be installed "by specialists".
I have seen the kit list from City Plumbing now and they have specified a 6.5Kw heat pump which is too big for my house. I don't think they took into consideration the MVHR. It seems to me the MCS/Heat pump industry is a mess and it is no wonder people who aren't paying attention end up with poor performing systems.

So nothing stating MCS, position of heat pump is defined by agreed plans, so that's not moveable.

So not many variables left except size of heat pump, which isn't stated on plans.

As mentioned above Panasonic are good, a small version of that would be fine. But you don't need a lot of the bits they will want to sell you.

Feet, flex hoses, isolation valves and anti freeze valves. I would really consider a direct cylinder. Especially if going for PV and/or battery, so you can make good use of ToU tariffs.

Edited just now1 min by JohnMo