Heat pump advice

Lewigreg081281

Hi all,

sorry if this has been asked before. 

Are heat pumps actually any good and what are the ball park costs?

we had someone around today and were told we’re eligible for the RHI payment from the government. 

The system was a Mitsubishi heat pump and Mitsubishi also give £800 as a one off payment. 

I’m awaiting the actual figures and you also need to book a £150 survey. 

Has anyone had experience of these? I’m sceptical. 

Our other option is a new boiler. 

Thanks 

Swipe

If you already have mains gas, you'd be mad to not get a new boiler

Verdigris

Correctly installed heat pumps are very efficient. I don't know the size of your house but an ASHP for an "average" 3-bedroom house might cost 7 or 8 thousand pounds, for the pump itself.

To work efficiently the water temperature is about half that of a conventional boiler system so radiators will need to be changed for larger ones or, ideally, underfloor heating fitted. The house insulation will probably need to be upgraded, too.

The more efficient you system, the higher the RHI payments you get. It is useful to have solar panels to supply "free" electricity.

If you want to read up on the subject I recommend this book:

Heat Pumps For the Home by John Cantor.

MattMattMattUK

Heat pumps are great in the right situation and setup, in the wrong situation and setup they are a bad decision, you need to establish what your situation is.

QrizB

Lewigreg081281 said:

Are heat pumps actually any good and what are the ball park costs?

we had someone around today and were told we’re eligible for the RHI payment from the government. 

The system was a Mitsubishi heat pump and Mitsubishi also give £800 as a one off payment.

You say "we had someone around", was this at your invitation? Because you should never buy anything from cold callers.

Heat pumps work but mains gas is still cheaper to run. Mitsubishi are a well-respected manufacturer.

It could cost £8-10k to have an air-source heat pump installed, but you will get most of that back over 7(?) years through RHI.

Lewigreg081281

MattMattMattUK said:

Heat pumps are great in the right situation and setup, in the wrong situation and setup they are a bad decision, you need to establish what your situation is.

So they said because our house is not efficient we’d qualify for the highly RHI. They inc in the cost replacing the majority of the radiators and did say they recommend having our Loft insulated again. Apparently our house is an E or D at best on EPC.

I need actual figures I’ve asked they send them but what he wrote down (from my memory) was total cost £16000 and then with the grants etc we’d get back £200 a month (You’d get a quarterly bulk payment) we’d receive back and a cost of £196 a month for the system on a 10 yr loan which we could move elsewhere or pay off early. When I asked what happens in the meantime until we get the quarterly payment he offered £660 to buy our old boiler which would cover the £196 until the quarterly grants etc came through. 

To me it seems confusing and is it simply better to get a new boiler. 

Verdigris

Also, bear in mind that the RHI scheme ends in March 2022. You have to have your system installed and commissioned by then.

I'm about to fit a heat pump in an E-rated house. I shall be externally insulating the walls to bring it up to a B or better.

Lewigreg081281

QrizB said:

Lewigreg081281 said:

Are heat pumps actually any good and what are the ball park costs?

we had someone around today and were told we’re eligible for the RHI payment from the government. 

The system was a Mitsubishi heat pump and Mitsubishi also give £800 as a one off payment.

You say "we had someone around", was this at your invitation? Because you should never buy anything from cold callers.

Heat pumps work but mains gas is still cheaper to run. Mitsubishi are a well-respected manufacturer.

It could cost £8-10k to have an air-source heat pump installed, but you will get most of that back over 7(?) years through RHI.

We invited them around it wasn’t a cold caller. It was greener living based in Sheffield. 

So a new boiler would be more efficient?

trhy quoted £16000 for the heat pump inc radiator replacement. Our home is a 4 bed semi detached. I’d say built in 70s. 

I’m awaiting figures but I’m sure it was just over 11k back off the government. 

Lewigreg081281

Verdigris said:

Also, bear in mind that the RHI scheme ends in March 2022. You have to have your system installed and commissioned by then.

I'm about to fit a heat pump in an E-rated house. I shall be externally insulating the walls to bring it up to a B or better.

Yeah they said that. If we went ahead it would be done before then. It’s the long term commitment for me and the initial outlay. 

It’s whether is it better to fit a new boiler and wait until they become more mainstream. 

QrizB

Currently, mains gas is too cheap (or electricity too expensive) to make air-to-water heat pumps economically viable.

Imagine you need 12000kWk/yr of heat. Using gas at at 4p/kWh that's £480 (or £570 if you include the SC).

Heat pumps run on electricity and deliver a coefficient of performance (COP) of around 3; for every kWh of electricity you put in, you get three kWh of heat out. So that same 12000kWh of heat will need 4000kWh of electricity. At 20p/kWh that will cost you £800.

So let's look at your estimate. You're asked to pay £16000 up front (or take a loan to cover it) but will get back £200 a month, £2400 a year, for 7 years. That's £16800 *but* you're also spending £300 a year more on your energy, £2100 over 7 years. So over the period you're £1300 down. After 7 years the RHI payments stop and you're stuck buying electricity not gas.

This ignores interest payments (which will make the heat pump more expensive; their quote of £196/month for 10 years is a total of £23500).

If there are significant energy price changes (if gas gets more expensive, or if electricity becomes a lot cheaper) it could in future favour the heat pump. But you need heating now, not in 1/2/5 years time.

If you don't have mains gas but instead have oil/LPG/E7 the financial case for a heat pump is stronger. @Reed_Richards recently replaced his dead oil-fired boiler with a heat pump and reckons it's pretty close on cost.

Air-air heat pumps have a higher CoP, typically around 4, and can make sense but they aren't eligible for RHI payments (supposedly, because they can also serve as air conditioning in the summer and UK Gov't doesn't want to encourage that.) @danrv has just fitted one of these (see this thread) and we're all looking forward to seeing how he gets on during the winter.

Edit to add: most heat pump discussion takes place in the "other fuels" sub-forum, there are several substantial threads there.

Rodders53

You need to do a lot of research and reading of threads on this forum, and others before deciding that a heat pump is a good idea.  There are a few happy converts around who have taken the time to work out how to use them properly.  Rather more with HPs pushed on them and have alarming electricity bills 'cos they can't understand how to use them efficiently.

Insulate, insulate and draught proof your home first.

Do you need a new (natural gas? LPG? oil? electric?) boiler today? Has your current one broken down and is it really beyond economical repair?

The price quoted sounds high and 10 years of repayments total £23,520.  An APR of around 8.5%  You'd be foolish to do that IMHO.  

I seriously doubt you'd get back £200 per month in RHI... £200 a quarter is possibly correct.  Do your own estimate here https://www.gov.uk/renewable-heat-incentive-calculator  As for grants towards the cost... means tested and then scarce if available at all?