ASHP and heating in a new build house.

[DREG]

Hi All

 

I have joined in the hope that I can rectify ongoing issues I have with my heating system and an ASHP. I bought  a new build house in the west midlands in 2022, hoping it would be warm and run efficiently with an air/water heat pump. It has been very disappointing so far. I’d like to get some advice/opinion on how to rectify the situation.

[Gone West]

@DREG Hi and welcome to the forum. If you post details of your situation on the ASHP sub forum somebody will be along to help you. Unfortunately I'm not that person.

[nod]

Probably be as well explains what the issue is Radiators heating slowly and not getting as hot as gas fired seems to be a repetitive theme 

[Ang]

I had ashp fitted 2022 will not get to a good temperature to warm my feet , miss sold also the company that fitted it went liquidation. Please please check all you documents insurance ect ect  in winter I can not get my home above 13 degrees/ at a cost of more them 20 pounds a day .

[marshian]

16 minutes ago, Ang said:

I had ashp fitted 2022 will not get to a good temperature to warm my feet , miss sold also the company that fitted it went liquidation. Please please check all you documents insurance ect ect  in winter I can not get my home above 13 degrees/ at a cost of more them 20 pounds a day .

 

That sounds terrible - have you got a "heat geek" accredited heating engineer to do a survey and see if it can be improved - as @JohnMo frequently points out the best way to make them work well is keep the circuit simple - weather comp for the flow temp - ditch buffers - big zones and have minimal thermostat interventions

 

I predict that poor installs of ASHP will be the next miss-selling scandal (Like PPI and Diesel cars)

[JohnMo]

1 hour ago, Ang said:

I had ashp fitted 2022 will not get to a good temperature to warm my feet , miss sold also the company that fitted it went liquidation. Please please check all you documents insurance ect ect  in winter I can not get my home above 13 degrees/ at a cost of more them 20 pounds a day .

Suspect a few additional details are needed 

 

What does you system look like?

 

Just UFH?

Retrofit or part of new build?

Floor build up?

Size of heat pump?

How do you operate?

Zones or single zone?

Buffer, volumiser or none?

How many manifolds?

Mixer and pump on manifold(s)?

 

You won't get warm feet from UFH, if you do there is something wrong generally.

[ProDave]

1 hour ago, Ang said:

had ashp fitted 2022 will not get to a good temperature to warm my feet

It should not need to get warm enough to warm your feet. Does it put enough heat into the rooms to get them to the set temperature?

[Iceverge]

How long are you running it for per day?

 

It will behave very differently to a gas boiler which are typically 5 times more powerful. 

 

Suppose you have a 7kW ASHP Vs a typical 35kW boiler. And your house needs 10kWh added to heat it from 10-20 Deg. 

 

Meanwhile during the heating up phase let's say your house is loosing an average of 5kWh. 

 

The heat pump is supplying 7kW -5kW so with the excess of 2kW the house takes 5hrs to heat up. It will use 35kWh to get up to temp. 

 

The boiler on the other hand has an excess of 30kW so will supply the 10kWh to heat the house in 20 minutes. It will use 10kWh to get up to temp. 

 

Now they're both up to temp and requiring 5Kw the boiler will run for about  5mintues every half an hour and the heat pump will modulate and supply 5kw continuously. They'll use the same evergy per hr. 

 

In both cases the house will be warm but the initial heat up phase will take the ASHP much longer.

 

With this you're faced with running it continuously, or with a very long lead in time to when you need heat provided. 

 

That's why they are less economical in intermittently heated houses than boilers. 

 

If you like to continuously heat the house both methods are on par.

 

 

 

 

 

[MikeSharp01]

1 hour ago, Iceverge said:

If you like to continuously heat the house both methods are on par.

So the target then is run continuously, well down to minimum modulation after which the HP will run intermittently. 

[Iceverge]

18 hours ago, MikeSharp01 said:

So the target then is run continuously, well down to minimum modulation after which the HP will run intermittently. 

 

It depends on your heat pump size Vs house heat loss. 

 

If you could manage to find a giant 30kW ASHP and pair it to giant radiators then you could run it pretty much exactly like a gas boiler.

 

If you could have a 5kW gas boiler then you would be faced with the same issues as a 5kW ASHP.