Heat pumps

matelodave

To my mind a heatpump is a bit like a leccy car. If it suits your lifestyle and you can afford it then why not do it.

However if it's going to cause a lot of disruption, doesn't match your requirements/lifestyle and costs significantly more either up front or in running costs then you've got to decide whether you can actually afford to stop burning stuff.

By all means be green if you can afford it or want too but lets limit some of the preaching and encourage people rather than beating them up.

I've just bough a nice grunty diesel because that's what I want and need for the type of driving that I do. I  dont live where there are buses (well one a week on Thursday morning) and most of my destinations dont have charging facilities that will get me there and back without a top-up.

It cost 25% less than the equivalent battery or even hybrid and it will do 600 miles on a tankful which saves me having to stop every couple of hundred miles for an hour or so to keep topping it up. Even worse when I'm towing as I'll have to do it every 150 miles and also have to uncouple the trailer to get into a charging bay if there's one available. 

I've no doubt that my next car will be electric in one form or another but hopefully the infrastructure and cost will have matured a bit by them. The same with heatpumps

Thirteen years ago I was a bit of a pioneer and as I was starting from scratch I though I'd go for a heatpump because I could afford to and although leccy was expensive the running costs compared well with my alternatives of LPG, storage heaters or oil. Thats not the case compared with mains gas or even oil at the moment and so you need to be happy to pay a significant lump of your income with a heatrpump.

Get the industry a bit more mature, bring down the cost of the equipment, installation and servicing whaich are all significantly more expensive than other forms of heating. Equalise the cost of gas and leccy and make sure that there's enough "green" leccy to power all this stuff and it will encourage people to move. 

matt_drummer

Our heat pump is being installed by Octopus next week.

I don't think the cost is at all outrageous and can't really see how it could be done for much less in the future.

The initial change from gas or oil to ASHP is always going to include a lot of additional work that won't be required when the heat pump needs replacing.

Ignoring radiator upgrades my cost is £11,000 before the BUS grant.

This is what I get for £11,000

The latest Daikin 9kW Monobloc heat pump with all the required controls
Hot water tank, buffer tank, magnetic filter, anti frost valves, pipework, insulation etc
Separate consumer unit, isolation switches and cabling.
Removal of my gas boiler and making good.
Removal of our old vented hot water system.
All waste disposed of
Capping and removal of gas supply
Initial survey, heat loss calculation, MCS compliance and follow up support
Four workers for up to a week, so around 20 days of labour.


When you go into detail and think about what is required, I'm not sure that there is a lot of trimming to be done.

matt_drummer

matelodave said:

To my mind a heatpump is a bit like a leccy car. If it suits your lifestyle and you can afford it then why not do it.

However if it's going to cause a lot of disruption, doesn't match your requirements/lifestyle and costs significantly more either up front or in running costs then you've got to decide whether you can actually afford to stop burning stuff.

By all means be green if you can afford it or want too but lets limit some of the preaching and encourage people rather than beating them up.

That is true.

If there is a choice available then people are free to choose whatever they want, I have no problem with that.

But eventually the choices available won't be the same as they are today and what's available could be more expensive than the choices we have now.

However, being more expensive doesn't necessarily make them bad, they are designed to different requirements, not burning stuff makes it more expensive, that is just the cost of cleaning up the air we breath.

Dismissing ASHP's purely on the basis of cost is not the full story. They are not being promoted as saving money and they won't save any significant amounts over an oil or gas boiler as things are today.

What they will do is cut down on energy use due to their efficiency and therefore improve air quality.

When people say `avoid them as they will cost you more than gas or oil' they are only telling part of the story and ignoring the environmental benefits.

So, I hope you don't think I am preaching, I just think a balanced opinion should be given rather than ones just based on financial costs.

matt_drummer

Does anybody know why this and other threads about heat pumps are moved here where fewer people look at them?

This section is titled

LPG, heating oil, solid & other fuels

Don't ASHP's run on electricity, why wouldn't discussions about an electric heating system be in the same place as those about NSH's and the like?

matelodave

TBH stuff like heatpumps, biomass and other "green" forms of heating should probably get a sub-forum all of their own where its relatively easy to get and disseminate specific info and opinions, rather than having to trawl through all the other stuff.

Clearer subforum headings would also help people navigate the complexities and avoid confusion - just my opinion you understand.

oliver1951

brewerdave said:

Re gas boiler replacement cost - relation just had a new boiler (not combi), pump and diverter valve done by local plumber for £2400 (as an aside - BG quoted ~ £5.5k ! ) .If you don't have to upsize rads and pipework gas much cheaper than ASHP

Well for me it wasn’t like that. I’ve had 5 quotes for replacement gas boilers incl rads and piping and they were from £9k upwards! Perhaps it’s more expensive here. Or maybe it’s because my existing system is so old and has to be replaced. For sure if you are only taking out an old combi and putting a new one in then it’s not too expensive. That’s not the case here.

oliver1951

Matt drummer, are you getting new pipe work? I’d be interested to hear how it goes for you. Clearly yours is a retrofit. Have you done a lot of other work in terms of insulation, double glazing etc, or was that already done anyway. Are you expecting it to cost more? I must admit the costs do worry me, but at the same time so does the co2. I have tended to keep my use of gas to a minimum because of that. But equally kept my use of electric low too. At least I thinks it’s low. Look forward to hearing how it goes. My ASHP has to go through planning unfortunately and they tell me it’ll take between 6-9 months. I know that was my response to so I spoke to my local councillor, who confirmed it!

matt_drummer

oliver1951 said:

Matt drummer, are you getting new pipe work? I’d be interested to hear how it goes for you. Clearly yours is a retrofit. Have you done a lot of other work in terms of insulation, double glazing etc, or was that already done anyway. Are you expecting it to cost more? I must admit the costs do worry me, but at the same time so does the co2. I have tended to keep my use of gas to a minimum because of that. But equally kept my use of electric low too. At least I thinks it’s low. Look forward to hearing how it goes. My ASHP has to go through planning unfortunately and they tell me it’ll take between 6-9 months. I know that was my response to so I spoke to my local councillor, who confirmed it!

@oliver1951

I would imagine quite a lot of my ASHP journey will be of interest to you.

Here is my thread on planning issues

https://forums.moneysavingexpert.com/discussion/6439483/air-source-heat-pump-planning-permission-required/p1


My install is replacing a gas boiler. The boiler is in good condition as is the rest of the heating system.

I chose to change to an ASHP for three reasons. Firstly I don't want to burn stuff anymore. Secondly, I am interested in the technology and want to see if I can make it work. Thirdly, I was worried about the rise in energy prices, particularly gas and wanted to fix my costs as much as possible.

We moved to this house in September 2021. It already had some solar panels fitted. I have worked out that I could fit more and add batteries. I expect to generate enough electricity in a year to run the normal house consumption and the heat pump.

What I export in the sunnier months pays for what I need to import when I don't generate enough from the panels.

I have enough batteries to cover the worst days of winter, so I will import at E7 rates. I may have some day time import but the income is enough to cover it.

I borrowed to install the panels and batteries, what that has done is fix my energy costs for the next ten years.

I don't need any pipework upgrades or changes other than what is required to fit the heat pump to the heating system.

My hot water system will be changed and obviously some pipework is necessary here but it is included in the cost.

They will also remove my gas and old water system, from next week I will no longer be paying the gas standing charge, so an immediate saving.

I have to change two radiators, a designer bathroom radiator (just because it's heat output couldn't be quantified for the MCS heat loss calculations) and an old radiator in the hallway that I would have liked to change anyway.

All my other radiators are big enough, they are not huge but they are all double panel convectors that are bigger than the house needed.

The house is well insulated and our heat loss is low, even included the all glass conservatory. 

It is quite easy to get a rough idea of how much it will cost to run the heat pump. I know how much we used in gas and it is easy to work out how much heat was put into the house.

The energy required to keep the house warm is the same whatever the heating source, if a gas boiler can heat the house, so can a heat pump.

The problems come when people try to run a heat pump like a gas boiler. You can't pump in loads of energy for an hour and then turn it off. They need to run continuously.

I know people who don't understand this, they see what the heat pump uses on start up, panic and turn them off to save money. They won't work like this, the house will be cold and it will cost a fortune.

Octopus install with a buffer tank. This ensures that the heat pump flow and return temperatures can be controlled with no problems. You need a difference between the leaving and return temperature of around 5 to 7c.

It is better if you can do it without a buffer tank as it can reduce efficiency, but to get the correct leaving and return temperature would require a perfect system.

The buffer tank makes sure it works.

With a buffer tank pipe sizes are not so critical, the heat pump and radiators are separated. It would even work with microbore pipe, it's no different to the gas or oil boiler it replaces. As long as the radiators are big enough the radiator piping won't be a barrier to having an ASHP.

Of course it is better to have perfect pipework and the highest efficiency possible but sometimes compromises need to be made.

It's also advisable to minimise heat loss as much as possible with insulation, but that would apply whatever the heating source was.


But, if your current heating system warms the house enough to make it comfortable then there is no reason why an ASHP can't do the same job if it is capable of producing the same amount of energy.


The cost of running an ASHP does not bother me and I do need to make sure it doesn't use too much energy as I am realy paying for it one way or another.

The calculation of cost is easy.

I used 12,500 kWh of gas last year, that is for heating and hot water.

The gas cost around £1,350 including the standing charge.

If I assume that my gas boiler is 90% efficient (which it probably isn't) then my ASHP needs to supply 11,250 kWh of energy to the house.

If I use a SCOP of 3.0 then the ASHP will consume 3,750 kWh of electricty.

At the current rates the electricity will cost around £1,125

Not much difference.

I would hope to get a SCOP of more than 3.0 as I think I can run at quite low flow temperatures bu I think a SCOP of 3.0 is a safe assumption.

Even if I got a SCOP of 2.5 my cost is still only £1,350, similar to the gas cost

The gas cost will probably be less going forward, I used 10p per kWh but it might only be 8p soon. That means the gas might cost £1,100 this year.

But it's not all about this year, who knows what gas will cost going forwards? At least I know what my heating will cost for as long as this system lasts.

For £6,700 I get some new radiators, a new hot water system that will be much better than what we have now and the heat pump.

I am receiving a grant and getting some work that needed doing anyway. The capital cost of actually replacing the boiler could be quantified as being between £3,000 and £4,000. Not so bad.


For me i am happy that I won't be burning anything in the future, if that costs a few pounds a month then so be it. Hopefully it will all be at least cost neutral over it's life, I would be happy with that.


I apologise (a little) for the long post but I though you deserved a full answer.

oliver1951

That’s a great answer thanks. I don’t have any solar pv, but it’s interesting that of the people I’ve spoken to with heat pumps so far, all of them have solar pv. I did get a quote a few years back (2019) , but bottled it. Recently I’ve had some more, but the pricing had doubled for the same 4.2 kw system. 

Reed_Richards

I bought a heat pump two and a half years ago and made a thread about it: https://forums.moneysavingexpert.com/discussion/6240076/i-bought-a-heat-pump/p1 - but that has got to page 43 now and so it's a bit difficult to read in its entirety.

In my case I was replacing an oil boiler.  I expected the running costs to be comparable and they were, maybe even a bit less for the heat pump, but that was before fuel prices went crazy.  I think at current prices my heat pump would have a comparable running cost to a gas boiler but an oil boiler would be cheaper than either.

I have been pleased with my heat pump.  Really the only thing I don't like about it is that is that it has made my heating system slightly audible whereas with the oil boiler it was completely silent.

I do have solar PV but it has very little impact on the running cost of my heat pump because you get the least solar power in winter when the heat pump is using the most electricity.  The fact that I have both is probably down to a desire to be "green".