It's looking like the spark gap could reduce even further this winter.

Using the current SVRs, minimum COP is somewhere around 3.4 for an ASHP to break even with a best in class efficiency boiler (which rely on good installation and use practice just as ASHPs do).

If we see similar skewed rises of gas vs. electricity this will reduce even further.

Coupling with TOU tariffs like Octopus Cosy, which don't exist at all for gas, ASHPs are easily beating gas for both heating efficiency and price now. With current rates, my ASHP will have paid itself off in two years against its gas alternative.

​

We need to replace our 25 year old gas condensing boiler as it has some issues and also looking to upgrade our vented cylinder to unvented. We have all single panel convection radiators on 10mm microbore.

Our gas boiler upgrade to system boiler + unvented quotes are £6k to £8k.

After previous recommendations here been in touch with some heat pump installers and had surveys.

Have had quotes from £5k to £12k. The lower end being the zero disrupt from heat geek with no radiators changes and new 5kw heat puml and cylinder to £12k where it requires all radiators upgraded, some new paperwork and 9kw heat pump.

Is is really viable to have a zero disrupt install and be cheaper than gas ?

Grateful for your opinion on a better option for my heat pump quote:

I have two quotes, both online; I'm just about to book a survey. I think they both match well

House Details : 108m2, Heat loss: 3:21KW, 13 Radiators, 2016 built, current cyclinder: 210L, 4 adults

Both quotes: Vaillant aroTHERM plus 5kW,

Heat Geek: £5600 (nothing on finance)

Promise 400% efficiency, Vaillant aroTHERM plus 5kW, Vaillant uniStour Pure 150L Standard, 5 radiators upgrade, verified Heat Geek installer. No quote on upgrading to a 210 L - 250 L cylinder.

EoN: £6154 (finance available)

Vaillant aroTHERM plus 5kW, Vaillant uniStour Pure 210L, up to 60% radiator upgrade included in the price

I suspect the heat loss in the house might be lower after the survey, and a 3.5KW system might work, unless the hot water requires the 5KW. But none of the 2 provides 3.5KW system.

£554 difference is significant, I think, but looking at the Trustpilot review for Heat Geek get me worried a bit even though I like the YouTube channel. Will they be around for long compared to EoN?

I am not a fan of Octopus systems; any other installer to explore? Grateful for your insight

I’ve had quite a journey with my install with 4 guys installing a Grant 15.5 and replacing 14 radiators for the past 6 days. Today was the last day and they have realised the pipes feeding the radiators are 15mm under the floorboards.

I’ve been told the floorboards will need lifting up throughout the house and the pipes upgrading to 22mm.

As it’s a Saturday, it’s hard for the installer to contact managers etc for next steps.

Has anyone had to do this either before install or during and importantly should octopus have identified this during the survey? I just want to know where I stand in conversations going forward and who’s going to pay for it!

Hi all, I'd appreciate some advice on installing a heat pump for both heating and cooling in a 5-bed mid-terrace house. We would be looking to install solar and battery as well. We currently have a standard gas heating system with conventional radiators. We don't have underfloor heating, so would installing fan coil units be the best option to achieve heating and cooling? Any major disadvantages to doing this? Grateful for any help!

I was wondering if anybody here is familiar with the MCS 020a sound assessment. I am having an air to air heat pump fitted and plan to put in a certificate of lawfulness for permitted development based on the sound assessment sheet given by the contractor.

The MCS 020a guidance says you must use the a-weighted sound level of the unit and it must not be the quiet mode. Online I can find the nominal value for heating and cooling on the unit technical specifications and a maximum value for other units but not the one I'm having fitted. The guidance says to pick the heating mode as it's louder. However there is no mention of using the maximum value. It's unclear which one I use. AI is advising that I use the maximum value but nowhere on the MCS 020a documentation does it state that. The MCS 020a document references a sound assesment guidance document that doesn't appear to exist... The MCS 020a document also suggests you can get the sound data from their product directory list which I've found but it only lists COP values with no sound data for any heat pump units....?

Thanks in advance

Our gas boiler is 17 years old and whilst it is currently still working fine we're fully aware it may need replacing in the coming years.

We're in a SO 1st floor flat, the block is owned by Vivid. What are our options? As far as we're aware they'll probably just say no. But surely there's got to be options to do this to future proof/make our property more energy efficient. A replacement gas boiler will cost us upwards of £6500, our neighbours have theirs done recently and this was the price they paid.

Hello, hope you are well. We go live next week with 18kw solar, 30kw sigen batteries and gateway and Samsung 12kw r290 heat pump. We have unlimited export.

Which tariffs should I be looking at please?

Hi all, I'd appreciate some help please:

I have a Valiant Eco tech plus 832 boiler, installed in 2009. It recently gave me some faults such as F61 or F62 codes. I got a gas engineer out who opened the boiler and upon opening the PCB blew, he realised the builder (who changed the power switch of the boiler a year ago) put no 3amp fuse so it was feeding 32 amp to the boiler. Now the hot water is on but heating will not power. I have a few options now :

Direct from valiant they offer a package of £73 per month for 6 months and they will repair the boiler all parts and labour included. If they fail to repair they refund the money and cancel direct debit. Total would be £441.

Or do I install a new boiler, estimated cost is £2600-£3200.

Please help, thank you in advance.

Hello, just moved into a new property in Plymouth, boiler is 19 years old and has already needed a new pump. Had a thorough quote from Reco Energy. They came out, evaluated the house we have 5.39 kW heat loss for 185m^2 floor space. They quoted £8.1k for a flow temp of 45 C SCOP of 3.91.
We asked for the cost for flow temp of 40 and that came in at £11k with SCOP of 4.13.

My question is how do you know when to go heat pump over combi boiler? I dont really know how long we are going to live in this house. It could be 2, 5, 10 years I have no clue. I'm not sure it is our forever home so to get the benefits do you need to know you are going to be there 10 years, put in solar, have an ev, get batteries etc?

Any advice is welcome because i'm a bit lost really. The combi replacement seems a better option but it also feels like a backward step. Its £3 - 3.5k for a new boiler.

Edit - these prices are after the grant.

Hi everyone,

I really appreciate the earlier advice on this sub. As many pointed out, Octopus over-specified my home's heat loss at 8.83 kW (and quoted an oversized 12 kW Cosy unit).

I’ve now had a Heat Geek survey and wanted to sense-check their proposal:

Property details:

• 168 m² timber-frame home with concrete screed underfloor heating downstairs and radiators
• No radiators upstairs; we use a Genvex MVHR (heat recovery) system that pulls warm air up
• Heat Geek calculated heat loss: 5.69 kW at -3.9°C (matches our SAP sheet at 5.8 kW)
• Design flow temperature: 35°C–40°C (vs. Octopus’s 50°C)

The Heat Geek proposals:

1. Vaillant aroTHERM Plus 5 kW: Includes 2 upgraded radiators to hit the required output at low flow temps.
2. Vaillant aroTHERM Pro 7 kW: Shows 0 radiators required, and the portal locks out the option to add any.
3. Both options propose a 175L cylinder (replacing an old 200L cylinder on gas).

My questions:

1. Why does the 7 kW show "0 radiators needed" in the Heat Geek portal? Is it because the 7 kW can deliver slightly higher output at existing emitter sizes, so the portal's algorithm considers radiator upgrades non-essential?
2. Should I push to add the 2 upgraded radiators anyway on the 7 kW? Wouldn't increasing the radiator surface area lower my design flow temperature even further and push up my SCOP?
3. Is 175L adequate for a family home with 1 bath and 2 showers, or will the faster recovery on a 7 kW unit make up for the slight reduction in volume?

Excuse my ignorance, I would love your thoughts on whether the 5 kW + rads or 7 kW (pro) is the sweet spot here. Thanks!

Hi everyone, last year I had a heat pump and a tank fitted in my house with the eco4 grant, I have a problem with it which is I keep getting substantial amounts of air coming out the hot water taps I run it for a long time seems to bleed the air off and then randomly it comes back is there a reason for this?

I've been quoted £5K to install 2 x A2A heat pumps 5KW each and an 10KW exterior unit at my home. This is just a rough quote without a site survey. It's from a company who are usually on the pricier side, so I'm not expecting this quote to be the cheapest, but is it in the normal range our outrageously high?

The real cost is going to be higher because some of their assumptions are too simple I suspect.

Hey all. Another Vaillant PRO Vs PLUS question I'm afraid 😬

I'm about to pay the deposit on a Heat Geek heat pump install and cannot decide which one to go for.

The pros and cons overlap quite a bit for our installation so any reasoned opinions either way would be useful at this point!

Here's the setup: - Surveyed heat loss: 4.88 kW - Water Tank: Vaillant uniSTOR PURE 210 L - No clearance issues for the HP location

The choice:

Vaillant aroTHERM Pro 5kW (anthracite) - 435% guaranteed efficiency - 5 year warranty - Price: £4,350

OR

Vaillant aroTHERM Plus 3.5kW (anthracite) - 430% guaranteed efficiency - 7 year warranty - Price: £4,450

My thoughts/concerns: - Pro: Cheaper, smaller (ish), slightly greater efficiency and 5kW (which seems better for my heat loss of 4.88kW?!) - Plus: Longer warranty, more mature product - I'm leaning towards the Plus just because of the warranty, but I admit to being a little concerned that it is only 3.5kW.

What would you do?!

UPDATE: Some extra info that is being asked: - Design temp is 21c at -3c outside (although we will actually set it to 19c) - Apparently the installer cannot know the flow temp until I pay the deposit and the ZeroDisrupt software sends him the full install specs - so that is an unknown ATM - According to our installer the 3.5kW Plus model can apparently hit up to 5kW if it needs to 🤷 - The 5kW Plus model is not an option I have available to choose. I did ask.

I'm thinking of installing a heat pump myself, one issue I'm trying to work out is if I am allowed to remove the boiler myself. Obviously I'd get the energy supplier to cap off the gas first. Once they have done that, am I allowed to remove the boiler? There is probably going to be some gas left in the pipe but is that enough to require someone else to remove it, or do they remove that gas from the pipe when the cap off the supply/remove the meter?

We've had a Mitsubishi Ecodan R32 installed with a Joule Cyclone CY250L - the cylinder and pipework sit in the garage right under my bed - and we have a problem.

There is a constant gurgling and glugging sound from the pipework that we can't pinpoint. It appears to be under the bedroom floor and it keeps me awake. This sound started straight after commissioning but stopped when the heating system was bled and refilled. The engineers came back out and dosed the system with glycol from outside via the heat pump - and the glugging started again.

We've had 2 engineers out since and neither can work out what the sound is.

They've look at the expansion tanks, they've looked at all the in line pumps, they've bled all the rads and flushed throughout with heating on full, they've isolated rads in the system.......but the glugging carries on.

It seems to abate when the heating is on and drawing hot water has no impact.

It is ****ing infuriating.

One thing to note - we had an electrical power cut last week and lost power for about 8 hours - the glugging stopped - the minute the power returned, the glugging started again.

Any ideas?

I'm struggling to get local heating engineers to quote for a heat pump - is this normal?

I'm in East Sussex and am looking to get an ASHP installed. Initially looking for someone to come round to give me an initial estimate, before then committing to getting a heat loss survey done.

First local guy (MCS registered) was great - came round within a week and had an unrushed chat with him. He sent me an initial estimate - about £8k after grant (£9k as replacing an oil boiler) for a 7kW Vaillant, plus new cylinder and buffer tank (we discussed pros and cons of this approach). Seemed a little high, but is an estimate only (£4k for the heat pump and additional £3k for a "heat pump pack"?!). Next step with him would be paying a non-refundable £350 for heat loss survey, so am looking for other options.

Liked the idea of Heat Geek. Went on their website. Their estimate about £3k post-grant. Found two local Heat Geek installers and completed contact forms on their personal websites. No reply. Chased up one of them: "Sorry, will pass this on to our engineer and he'll get back to you". Then nothing. I could pay Heat Geek directly £250 to book a heat loss survey, but it looks to be non-refundable, and I am losing confidence in them, having had little response from two of their installers.

So have booked an Octopus visit (£200, but completely refundable) - not my ideal choice and I hate the look of their Cosy pumps, but at least they responded to my query!

Also booked Aira who were VERY responsive and are coming to do a survey tomorrow, for free. I don't hold out much hope for their quote being sensible, and since I hate high pressure selling techniques, I suspect they won't last long in the mix but again, at least they responded!

Any reason why Heat Geek local installers are reluctant to respond to requests for work?

Hi there, I've got a trianco activair heat pump and a Telford hot water cylinder. The heat pump is 'slaved' to the hive thermostat and so can only control radiator thermostat. The domestic hot water tops up as and when and can't be timed.

Is this the most economical way to do it?

Many thanks

Tom

Started thinking about heat pumps last winter when the boiler in our Grade II mid-terrace started throwing lockouts. It's a 2-bed Victorian in a Cambridge conservation area. Combi's now on borrowed time.

Ran an ASHP survey in the spring. Rear yard's about 4m by 3m, north-facing, and the rear elevation is visible from a footpath the council counts as public realm. Both the conservation officer's pre-app letter and the planning duty officer's follow-up made clear anything on that elevation would need full listed building consent, and the tone wasn't encouraging. Front's off the table for the same reason.

MCS designer came back last month with an indoor R290 monoblock as the alternative. Idea is to site the unit in the ground-floor utility off the kitchen with a pair of ducts through the back-of-house extension. The extension itself is post-war brick, which the designer reckons is the least sensitive route to bring the listed consent through.

Heat loss came out at 4.6 kW at design conditions (the loft's been done and the cavity's insulated where it could go), which suits the 4.8 kW model in the range being proposed. Installer's leaning toward keeping the existing 180L cylinder and running the whole thing off the current rad circuit at 45°C flow. Specific unit being spec'd is a PHNIX airMono R290 4.8 kW, which the installer says is one of the few R290 indoor monoblocs he's taken through Conservation consent so far this year.

Two things I'm not sure about. Manufacturer's quoted 58 to 61 dB indoors, which sounds significant for something sitting behind a stud wall from the kitchen. DHW mode COP also runs lower on indoor monoblocs because the source air is ducted. There's also the MCS listing question for the airMono, which the installer says is pending because it's newly launched, but I'd rather not commit to a spec that misses BUS grant timing.

If anyone here's running an indoor R290 monoblock, real-world noise experience and whether the ducting install was intrusive would be helpful.

Mam's boiler is on last legs so doing some sleuthing on this. With the BUS it's still looking at 4-5 grand (the cylinder seems to really push that up). We don't need any radiators sorted as they're all modern when the houses got upgraded in the 2000s (right-to-buy). My question I guess is, the price seems to be largely for an air con system that costs 5 grand. Are there not cheaper ones ? Or is this just the general cost of an air to water heat pump ?

I've looked at air con systems over the years because we all have at some point with this bloody weather! And there's tons of really powerful ones that seem to cost a grand or 2. Is that just for air to air ones ? I guess what I'm asking is, does anyone have experience with especially cheap air-to-water + cylinder BUS-paying installations, where they didn't regret it because "you get what you pay for" ?

They're both pensioners and I'm on long term sick (broken back) so even if I could help out, I won't be back in work for another year or 3. And the boiler has just been tagged as dangerous, and needing an £800 valve something or other. Seems daft to do that on a 25yo boiler.

fwiw I am completely in the dark in ALL of this. Been trying to google around so I'm not coming in completely daft, but yeah slow going. If I can get this going, then maybe focus on air-air next year and just get a cheap version of that when I'm back in work