@john-castle welcome to the forums. Feel free start a new thread dedicated to your heat pump and let us know what the issue was and how you resolved it. Sounds like an interesting case, and it'll be interesting to hear how you had the refrigerant issue diagnosed.

@transparent hello. Doing a big renovation and need to move the unvented tank and boiler so thinking rather than paying to do that go heat pump. Boiler and tank are about 10 years old. But im consuming lots of Homeowners QA which is very good and Heat Geeks on YouTube and some of what I’m learning is not what some installers (even HG ones) are suggesting. Like why do I need a buffer or volumizer in a 4 bed with 13 rads 28mm down to 22mm then 15mm to rads. Can’t I run open loop?

@adamk You defernatly do not need a buffer and possibly a volumisor depending on how many radiators you have open loop and the unit you choose. Yes, you can run it on open loop.

Posted by: @adamk

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@transparent hello. Doing a big renovation and need to move the unvented tank and boiler so thinking rather than paying to do that go heat pump. Boiler and tank are about 10 years old. But im consuming lots of Homeowners QA which is very good and Heat Geeks on YouTube and some of what I’m learning is not what some installers (even HG ones) are suggesting. Like why do I need a buffer or volumizer in a 4 bed with 13 rads 28mm down to 22mm then 15mm to rads. Can’t I run open loop?

The installers who insist you need a buffer are ones to be avoided.  You may need a volumiser which has only 2 ports.  These dont suffer the problems that buffers suffer.  Very likely you dont need that either, but neither will it do any harm. 

Correctly-sized (large) diameter pipework is a lot cheaper than a volumiser, @adamk
... and takes up much less space!

But installers can make a lot more profit from fitting an impressive-looking tank.

Get the heat-survey done for your house, and then share the details back here in a new topic.
We can check that there's sufficient volume in the system which is being specified.

As you're part-way through a renovation project, make sure that the survey is based on the insulation levels and layout which will eventually be there,
rather than what the surveyor can currently see.

If possible, go for underfloor heating (UFH).
That offers a much larger heated surface than a radiator can.

Ask here if you'd like to know more on that.
I have photos and diagrams which I can post as required.

Posted by: @transparent

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Correctly-sized (large) diameter pipework is a lot cheaper than a volumiser, @adamk
... and takes up much less space!

But installers can make a lot more profit from fitting an impressive-looking tank.

Get the heat-survey done for your house, and then share the details back here in a new topic.
We can check that there's sufficient volume in the system which is being specified.

 

As you're part-way through a renovation project, make sure that the survey is based on the insulation levels and layout which will eventually be there,
rather than what the surveyor can currently see.

If possible, go for underfloor heating (UFH).
That offers a much larger heated surface than a radiator can.

Ask here if you'd like to know more on that.
I have photos and diagrams which I can post as required.

ive already posted in the ASHP section with quite  few details.

im waiting for Mars to give me the details of an installer that might be suitable.

Hello and thanks for letting me join.

My partner and I are in the midst of planning an extension to our victorian semi in the Nottingham area and working out whether to replace our ageing boiler with a heat pump as part of the works.

Matthew

Welcome. 

If you provide some more information about the property and anything you have already found out I'm sure you will get some helpful ideas.

Thank you.  I'll try to put a summary together in a new thread.  Might take me a day or so to pull that together.

Hi I am in my 70s and about to get rid of the gas boiler. We live in an old house that has been extended several times. Half of the rooms in the house we don't use much if at all. We have quotes for ashps and for IR panels. We currently heat one room with Herschell panels and love the quality of the heat. My preference for the future would be to heat the core of the house with an ashp and the rooms we dont use with IR panels just to stop any deterioration. A few hours at night would do this - we are on the Octopus agile tariff. My rough calculations suggest this approach would use fewer Kwh even allowing for the ashp cop / scop. Any help would be great as I am not a heating engineer 🙂 

Welcome to the forum and please feel free to ask as many questions as you need to, no question is 'stupid'.  If you havent already can I suggest you read the ABC guide to ashps here, it should help your understanding.

Unless you dont already have radiators in the rooms in question, Im not sure why you would heat some rooms with IR panels and some with the ASHP.  The IR panels will emit the same energy as you put into them, the ASHP will emit three times the energy you put into them.  If you want some rooms cooler turn down the lockshield valves on the radiators, however be aware that rooms are rarely isolated thermally from each other so the saving by doing this is much less than you think, in fact it can even cost more money because you are trying to heat the 'cool' rooms from the radiators in the warm rooms.  Remember houses continue to lose heat even when the heating is switched off!  If you post your rough calculations Im sure someone (possibly me) will comment however.

Also bear in mind that a condition of the BUS grant is that the system installed is capable of heating the whole house.

Have you had a heat loss survey and quotes yet or are you early on in the process?

Hi James.

Apologies if what follows is all wrong - just knowing that it is wrong would be progress 🙂

Thanks very much for your speedy reply and your warm welcome. The resources your site provide are very helpful. Should probably have said in my first post that although I’m not a heating engineer, my background is in Science/Computing and I have a basic understanding of the general concepts of ASHP’s and IR heating.  It's very interesting to try and work out  how these heating systems would perform in a house like ours with about 50% of the rooms unused and the fact we are home all day. 

“Unless you dont already have radiators in the rooms in question, Im not sure why you would heat some rooms with IR panels and some with the ASHP.”

When we had a new kitchen fitted last year we replaced the old AGA (which heated the kitchen) with two 800w IR panels. It’s subjective but we find the radiant heat from the old AGA and the IR panels much more pleasant than radiators. The IR panels heat the kitchen much quicker than our 29kw 8 year old gas combi boiler heats the rest of the house.

So my understanding (which may be completely incorrect, that’s why I'm posting here 🙂) is that the heat pump will be most efficient if our target temperature and our fall back temperature are quite close together, say 20 degrees and 17 degrees and that all the rooms are heated at least to around the fall back temperature. The heat pump will also be more efficient if it runs on an “open loop” system with no individual radiator control,  buffer tank or volumiser. 

From experience, IR panels can be turned on when or just before we enter a room.

So the question I hope you can help with is which system would use the least electricity given the fact we are at home all day and only use a few rooms. The ease of control of the IR panels may mean we would be using less Kw at any one time than a heat pump.The one quote we have so far for a heat pump is for a 14kw Mitsubishi high temperature ashp. Heating our largest room with IR panels would use about 2Kw. Most rooms use much less. We would only use more at times when the internal room temperature drops below 13 degrees (our setback IR temp) 

We have three quotes in, the one for the Heat Pump is cheaper than the 2 IR quotes because of the grant. The 3 quotes so far were not based on a full on site Heat loss survey. We have 2 full on site surveys coming up in the next few weeks. 

If we go the IR route we will us a sunamp system for hot water. 

Peter