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Kingspan heating (or lack of) issue


Lynford

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Hi, I wonder if anyone can help please ?

 

My In-Laws bought a bungalow a few years ago that had been fitted with a Kingspan Aeromax ASHP and have had problems with it ever since. 

 

Theres a whole list of stuff that’s been allegedly done, and by several people. The bottom line is that they get plenty of hot water, but when conditions are cold they don’t get any heating.........which is kind of when you need it ! We live an hour away and I’ve been letting them try to deal with this but I feel I need to step in as they are throwing good money after bad and no one they have around seems to truly know the system. 

Having read this forum there seem to be some very knowledgable & helpful people about. I notice that the Kingspan are, like a few others, just a rebadged version of a make called Carrier. I also notice from some extremely insightful posts from JSHarris that these units aren’t very well set up for the UK winter.

 

Can anyone give any advice please ? If I need to buy one of these command units to reprogramme the system, assuming anyone knows the required parameters, then I’m happy to do that. 

 

For the record, I have no experience with these systems, or heating in general but I am a mechanical engineer with some electrical experience, so I should be able to do most stuff. 

 

Thanks for any help.

 

Cheers,

Lyndon

Edited by Lynford
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Welcome

Probably the first thing to do is a sketch of the total setup.  That should help with setting up.

What sort a thermal emitters (posh term for radiator/under floor heating) do they have.

Is the system set up to deliver at a very high temperature i.e. is the water heated initially by the ASHP and then an immersion or the internal resistance heater in the unit.  This will be expensive to run if it is.

Does it have a large/medium/small thermal store, or just an ordinary looking hot water cylinder.  Are there any buffer tanks.

 

One problem to overcome is that there is a difference between space heating and domestic hot water heating, they do different things, at different temperatures and at different times.

 

Also, do you have any idea what the heat loads for the house are?  Your parents may just have an undersized unit set up to deliver primarily hot water.

Edited by SteamyTea
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Welcome.

 

The unit is the same as our Glowworm, a re-badged Carrier, and the problems almost certainly relate to the installation and set up.  At the time that this unit was installed, Kingspan had only really dipped their toe into the heat pump market, as had Glowworm.  A consequence may well be that both the installation design and the setup could be far from optimal.

 

As above, we really need to understand the installation design.  There were several different options, particularly with the way the switch from heating to hot water mode is done.  I have to say that although these units will deliver hot water, they are a pretty expensive way of doing it - a hot water tank with an immersion heater running from E7 would almost certainly be cheaper.

 

The external unit can operate in several different modes, with settings for each programmed via the Command Unit.  Sometimes this is included with the unit (it was with our Glowworm badged one), sometimes it isn't.  This is what it looks like:

 

577808d146602_GlowwormCommandUnit.thumb.JPG.429dcc5b757b74a818b37c76cc2f6319.JPG

 

The only difference between the Carrier, Kingspan or Glowworm Command Unit is the name on the front.  Both Glowworm and Kingspan sold systems without the Command Unit, that were pre-programmed at the factory.  These systems cannot have their settings altered once installed unless a Command Unit is connected, but whether or not the settings need to be changed on your in-laws installation depends very much on how it is connected up.

 

The ASHP itself is controlled by a number of "dry contact" connections that are ELV, so safe (they run on an isolated 12V supply that's internal to the unit).  All any control system has to do is switch one of these connections to a common connection in order to turn that function on.  The main connections in most installations are just the heat pump on/off one and the hot water one.  There are also options for an "eco" mode, a "quiet" mode and setting to unit into cooling mode, for air conditioning.  The chances are these aren't used, and only the on/off and hot water connections are used.

 

If the heat pump is just turned on, by a contact closing the on/off to common connection, then it defaults to heating mode, and will deliver a flow temperature to the heating system that is dependent on the internal settings.  The default settings for our unit were not optimised for the UK climate at all, I found.  The heating flow temperature is set to change with temperature, so as it gets colder the flow temperature increases.  In heating mode the unit will only work with underfloor heating or low temperature radiators - it will not work well with conventionally sized radiators at all, they have to be much larger in area because of the relatively low flow temperature.  This may be an easy thing to initially check.

 

When the hot water connection is closed, the unit switches to high temperature mode and delivers a flow temperature of around 50 deg C.  I have to say it does this under duress, and although it works, it is not at all efficient when running that hot.  The control system in the house should include a valve that allows hot water to have priority, so that when there is a call for hot water this valve directs the heat pump output to the hot water system and at the same time the heat pump is switched to hot water mode.

 

Just like a combi boiler, the heat pump cannot normally (if it is connected and installed as the manufacturer intended) deliver hot water and heating at the same time.  When heating hot water it won't deliver heating and vice versa.  This means that if the current hot water settings are asking the unit to deliver hot water when heating is needed, then it won't provide heating during that time.  The idea is to have the hot water set to heat up the tank when heating isn't needed, say over night, or perhaps when no one is home during the day, so there is always a tank full of hot water available. 

 

If you can give us a bit more information, ideally an installation diagram, and confirm whether or not the system has a Command Unit connected, I can probably have a go at working out what might be causing the problems.

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I bought a Kingspan ASHP on Ebay and at the time command units were hard to come by, I phoned carrier in America and they gave me a telephone number of their depot in Southampton ( I think) which had them  In stock and they sold me one. ( I am yet to install it so will be watching this thread with interest).

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Thanks so much for the replies, gives us some hope of finally getting somewhere with this. Very kind of you Gents.

 

We are are up there tomorrow, I’ll see what the FIL can dig out in terms of diagrams, paperwork etc and I’ll take some pics. In honesty after reading JS Harris’s post the size of the radiators worries me.........I think they are common or garden heating system rads.

 

Anyway, thanks again. I’ll report back with any info tomorrow. 

 

Cheers,

Lyndon

 

 

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If the radiators are small, standard sized ones, then they won't deliver anywhere near their rated output, due to the lower flow temperature from a heat pump.  There are ways around this, including some simple things, like adding quiet fans to each radiator, that will increase the heat output.

 

We'd best wait until your return with the info before making further suggestions.

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Just to add to what has already been said, we had a radiator based system fed by a heat pump in our last house.  15mm pipework to the radiators which were massively oversized (around 3 times the size compared to a conventional high temperature system) to allow them to emit the low temperature heat - in our case a flow temp of 33C when it was 0C ambient. 

 

A lot of early ASHP installation, the ASHP was touted as a direct boiler replacement.  Whilst they can produce highish temperature water, they do so at the cost of efficiency.  Failing to upgrade the DHW cylinder to one with a 'heat pump' coil, i.e. massively increased surface area compared to a standard cylinder, and not replacing radiators with correctly sized ones / keeping existing microbore pipework were common problems.

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Thanks Gents,

 

I’m up here now and things are a little clearer for me in some areas and a little less in others !

 

I have a load of pictures (paints a 1000 words etc) and some info over what has been asked. 

 

  • I’d got it wrong over the hot water - This is being provided by the immersion heater in the tank, not by the ASHP. So we have neither heating not HW from the ASHP.
  • ‘There is no command unit as per JS Harris’s earlier picture. 
  • Apparently the radiators were originally the wrong type, but were changed and are correct for ASHPs. 
  • There is no installation diagram, as it’s fitted here. Just the manual we can find online to say how it should be fitted. 

 

I’m sorry, I don’t know how to upload pics in the middle of a post so I’ll put them in their own post with an explanation. 

 

Cheers. 

 

Edited by Lynford
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Controls

 

The Timeguard one on the right is to control the HW immersion heater. The Danfoss one on the left is supposed to be the ASHP heating and HW. 

 

The wiring is is within the Danfoss box that is sitting above the Kingspan diagnostic box. 

 

 

CE545869-8944-4848-8328-802E8B7A4EBA.jpeg

CAA43EF3-CEDB-4B68-A126-3BC0EBD2BE3E.jpeg

B6C02741-35FF-49E9-A9CE-CED212BAC93F.jpeg

5152A866-153F-4C5C-8068-34AEE3AF1403.jpeg

Edited by Lynford
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I’m told that this diagram from the manual is the wiring within the Danfoss box as above. However I’m not so sure as some of the numbers don’t correspond and on here it says that 3 & 7nshould be linked out, which they aren’t in that Danfoss box. 

 

 

5CC344BA-4503-4542-8848-B90DFF4DE858.jpeg

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OK, you have the external diagnostic indicator box fitted, and that mimics one of the LEDs that is fitted on the circuit board in the heat pump.  That is green, which means there are no errors being reported by the heat pump itself.  You can get a lot more detail by removing the cover of the heat pump and looking at the full diagnostic indicators.

 

First off, in case you don't have it, here's the manual for that unit:

 

Kingspan_Aeromax_plus_Installation.pdf

 

The diagnostic codes are detailed on page 23.  If you choose to do this, use caution, as there are live connections that are exposed when the outer cover is removed, and I can tell you from personal experience on our smaller model of the same heat pump that in removing the outer cover with the power on you can get it to touch a live terminal as you take it off(gave me a heck of a belt!).  Best to turn the power off, then remove the cover, then turn the power back on. 

 

Also included in that manual is the wiring for the wiring centre that you have taken the cover off, and that for the programmer and thermostat, so it would be a good idea to check that it's wired as it should be.

 

Post back here with what you've found and we'll try and help further.

 

 

 

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Thanks Mr H. 

 

I see see what you mean about getting a packet off the cover - The live terminals aren’t exactly covered well !

 

Unfortunately this may be a slow process as we live an hour away and I can only get up there at certain times.

 

I did have the cover off and found only one of those LEDs (D805) on when I turned the power back on.

 

 

 

 

6BD90F6B-067D-4283-8E46-2501942748B0.png

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OK, all's normal with the heat pump, that indicates no faults and the unit should be operating normally, so the problem has to be elsewhere.  I suspect that the wiring in the wiring centre may well be wrong, and the heat pump isn't getting the call for heat signal.  From your photo it looks a bit of a mess in there.  I'll have a long look at it later and see if I can spot what the problem is.

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Thank you. 

 

This system has actually worked before, it seems that as soon as the temperature drops it goes off again. 

 

The wiring in the ASHP didn’t look too great either, loads of wires with makeshift numbers written on tape that is wrapped around them, also not in the terminals very well. The next time I go I’m going to take a handful of bootlace ferrules and tidy that up / make sure they are in properly.

 

Thanks again.

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8 hours ago, Lynford said:

I’d got it wrong over the hot water - This is being provided by the immersion heater in the tank, not by the ASHP. So we have neither heating not HW from the ASHP.

 

Right.. that statement doesn’t make sense ..!!

 

- firstly, in picture 4 of your general pipework post there is a 3 way valve

- secondly, that’s a heat pump indirect cylinder which means it has a coil. 

 

Just out of interest, check the lever is free and the 3 way valve isn’t stuck. Running at 38c or so, and with the hot water as priority but being heated by the immersion, this would mean the heating doesn’t kick in. It may also mean the 3 way valve is back to front or is in “W Plan” configuration.  

 

My gut feel is the 3 way valve is stuck, and this is in permanent DHW config but the immersion has taken over. 

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10 hours ago, PeterW said:

My gut feel is the 3 way valve is stuck, and this is in permanent DHW config but the immersion has taken over. 

Could that cause the heating system to drag heat out of the cylinder.

So the house is being heated by electricity and not the heat pump.

Have a look at the electricity bill and see if it is very high.

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