[P962c]

Since Installation in May 2021 the system has been working well with only one minor problem.

This was due to a diaphragm failure in one of the sealed expansion vessels. The design life of these units is around 3 years so failure in the fourth year is not too bad. The indicator for the failure was a lower than normal pressure reading in one part of the system. This was found in the annual service. This does not stop the system working so the only downtime was to replace the faulty unit.

The cost of replacement was £180.00, with a replacement time of around twenty minutes.

The system is serviced annually at a cost of £294 per service.The service is carried out by the installer in accordance with Mitsubishi warranty requirements. The pump itself still looks like new despite being outside in all winds and weather, so no issues with build quality. The pump is still as quiet as the day it was installed

The MELCloud App allows the control of the entire system from anywhere and issues alerts so any appropriate action can carried out. We have not had any of these.

Am I glad I had the system installed? Yes, the system is very sophisticated and the built in self protection systems are very impressive and so far reliability has been impeccable. I am glad I no longer have to pay for gas. What the government needs to do now is separate gas and electricity prices and abandon all the levies on energy prices. This would make these systems more attractive.

You can read my previous review on this thread: Living with an Air Source Heat Pump 2 years on

[P962c]

Picture of the Heat Pump


Tank and control Box

[DebF_EONNext]

Thank you for sharing your experience @P962c it's great to read that it's still going strong after 5 years! It's interesting you mentioned about the servicing as I didn't even think about this 🙈 but it makes sense as it's an alternative boiler essentially!

I agree that it needs to be more accessible for everyone and more needs to be done, however there are schemes out there such as the boiler upgrade scheme and at the moment we also have an offer on exclusively for community members to get £700 off! If anyone is interested you can read more about it and how it works by visiting this thread 👉 Thinking about buying an air Source Heat Pump? EON Next Heat Pump Offer NOW LIVE!

[Indyk_EONNext]

Thank you for sharing such a detailed, real-world update! @P962c it's great to hear that such big changes can be beneficial after all. With the pictures you have shared it really does look like new, and it's good to know that no matter what the weather it's strong and reliable with the heat pump being outdoors I think that would be a big worry for me.

If anyone thinking about getting heat pumps and is curious about the installation process, take a look at this post shared by @Anasa_EONNext EON Next Heat Pump Installation Journey 😊

[Connor_EONNext]

A lot of amazing information here @P962c - thank you for sharing 😀 That repair time is very quick, correct me if i'm wrong, but I'd imagine there's less that could go wrong with a heat pump in comparison to a boiler, although - there is the control box and the pump itself so I may be wrong.

Could I ask, how does it hold up in different weather conditions? For example, a frosty or rainy day?

[P962c]

Hi Connor,

Talking to the installation engineers the only major thing that could fail is the main compressor, which would mean the pump wpould need to be replaced. The working life of the pumps is around 20 years (similar technology as a refridgerator). The only other parts are things like the sensors which can be replaced easily.
The pump fan bearings are sealed for life.

The control system is totally electronic so can be replaced easily. Basically one large PCB.

Parts on the tank can be replaced easily. The expansion vessels are the parts most likely to need replacing relatively frequently, as exprienced on my system

As far as weather conditions are concerned the pump itself is protected from freezing conditions by an in built heater activated by temperature sensor.
when activated the pump stops and only restarts when the pump is clear of any frost, etc.
The outside piping is fully insulated and the water in the heating side of the system contains glycol. so cannot freeze.

The country with the highest use of air source heat pumps is Finland. The specification of these pumps is the same as those supplied in the UK.
We have experienced temperatures of -12DegC without any issues at all.

The pump electrics are sealed against water ingress as are all the external connections. The emergency on/of switch is als IP rated to cope with extreme weather conditions.

The pump has drainage points to allow any water entering through the front of the pump to drain away.

Our heat pump as coped with persistant torrential rain, hail storms and very high winds without any problems.

Hope this answers your questions, pleas elet me know if you would like any more information.

[TheRealAdrian]

@P962c
”The design life of these units is around 3 years”
That is appalling. They ought to have a design life of at least 20 years like the rest of the system.

[P962c]

Hi TheRealAdrian,

I agree the design life of the expansion vessels is very far from good.
As bit of back ground information, the tank comes from Mitsubishi with all the parts for their part of the system pre installed. The pressure vessels are supplied and fitted by the installation company along with all the plumbing equipment required. The size of the expansion vessel is stated in the documentation supplied with the tank.

The expanasion vessel in question is on the heating side of the system which is subject to more work tna the one on the hot water side. The diaphragm is subject to a higher fatigue failure rate.

This does, of course, not excuse the low design life.

[rwh202]

The £298 annual service - ouch! That’s a chunk of our projected savings wiped out and the break even time pushed out even further.
Our gas boiler service and safety check is £95 and seems a lot more involved than what I suspect is necessary for a heat pump.

[meldrewreborn]

@rwh202

agreed. My gas bill is currently £670 per annum. And my boiler is a chronologically gifted one installed in 1988. I could replace it with a more efficient model but it’s not cost effective to do so. Changing to a heat pump makes no financial sense at all as even if it could break even on running costs, I would never recover the capital investment.

I suspect I’m not alone in my reasoning. Like many the environmental impact is not something that I take into account in my consideration. The government has levers that it could use to dissuade consumers from using gas but recognises it would be electoral suicide to use them.