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Help required wiring my ASHP/UFH


joe90

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2 minutes ago, dpmiller said:

does the valve's microswitch report back to the ASHP?

 

Dunno? I will recheck wiring re NC @ NO .

 

(I need another coffee already?)

Edited by joe90
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My understanding is that yes, it would normally be in the heating position and should move to the DHW position on command.  I take it that you have the 3 port valve wired between N and terminal 10?  Reading the manuals, the 3 port valve controls seem to be between terminal 18, terminal 10 and N.  The description in the Carrier information shows that 18 (L) and N are the power supply to the valve, 10 (L) is the signal.  Not sure what this means, but it might be an idea to disconnect the valve and stick a meter between N and terminal 10 and then N and terminal 18 to see what happens when the 3 port valve relay operates. 

 

The Kingspan GMC board will have been pre-programmed with a load of settings that don't seem to be clear from their documentation, but the Carrier Installation Manual (copy below in case you don't have it) has a bit more information at the top of page 11 that may help.

 

30awh004h Carrier ASHP Installation Manual.pdf

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5 minutes ago, joe90 said:

Dunno? I will recheck wiring re NC @ NO .

Yup, three way valve wired correctly

 

on the three way valve pipe “B” goes to DHW and “A” to heating, is this correct as I vaguely remember this being asked by someone else!

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My wiring diagram shows no connection to 18 and Jeremy,s note above says “if three way valve has spring return do not use 18” mine is spring return hence no connection to 18 (I suppose).

 

right, during testing with a multimeter the 3 way valve is no longer activated ?

 

i have checked all the parameters (100 to 158) and noticed I can only set 113 (heat water set point) if 100 is set to 1 (fixed water temp value dry contacts) do they refer to dry contacts as remote room thermostat or tank stat?. I tried setting 100 to 4 as I want the command unit to act as room stat but if I do I cannot set the (113) water temp (113 simply not available).

 

the GMC board is flashing “normal” but the ASHP will not kick in for heating (temp set high to force on in warm house) or DHW and I have drained all hot water and set tank stat high to call for heat.

 

i have noticed that the “schedule activated” icon (23) on the command unit is flashing but there is nothing to say why?.

 

Managed to get the ASHP to fire up and pump running by shorting 13 and 15 on the ASHP so appear to have a wiring problem within the house.

Edited by joe90
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Looks like it's once again taken time to transfer data to the GMS board.  I think the GMC board may be effectively unprogrammed when new, and that perhaps the Command Unit only actually sends data to change setting when a parameter is selected and changed.  That would make sense, as there would be no point is storing data to non-volatile memory on the GMC board every time the Command Unit interrogated a setting.

 

It looks as if using the Command Unit as the thermostat and programme may conflict with wanting to use dry contacts to switch to DHW mode, from the sound of it.  This isn't something I've ever played with on mine, as I just use dry contact control (similar to the way Kingspan control this unit) and I don't use the DHW function.

 

Best bet might be to get a dry-contact programmable room stat and use that to control the heating, then use a dry contact tank stat to control the DHW.  You want DHW to over-ride heating, so the dry contact tank stat can connect directly to the ASHP terminals 13 and 15, which will heat the DHW whenever it needs it, including moving the position of the 3 port valve.

 

 

 

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This once again shows how the firmware in these things is somewhat clunky and needs another level of development.

 

Perhaps you should go through every parameter and change it, even if that means change it, then change it back (if it was correct to start with)  That would surely ensure all parameters are stored properly.

 

My own HP has several "stupid programmer errors" like it will not allow you to change the hot water temperature set point, unless the heating is actually on and running. So if the room thermostat has turned the heating off and you want to change the DHW setting, you have to go and turn up the thermostat to bring the heating on, make the change, then go and turn the thermostat back down again.  Imagine the palava to change the hot water temperature in the summer when the heating is not on at all.

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Great, the good news is I am actually getting warm water from the ASHP. The bad news is the programmer I bought for DHW (for when and if we get E7) is faulty so that’s why the stat was not calling for DHW (easily fixed). I am going to let it run for a few hours then I will try to get heating working. THANKS GUYS ?

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Just now, ProDave said:

Just be careful that any thermostats / controllers you connect really are volt free dry contacts.

 

Ha, that’s one mistake I won’t make again!!!!, cost me £££££.

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1 hour ago, joe90 said:

Yup, three way valve wired correctly

 

on the three way valve pipe “B” goes to DHW and “A” to heating, is this correct as I vaguely remember this being asked by someone else!

 

Ha, oh no it’s not ?. ASHP is running, pump running, three way valve operating all ok BUT, the three way valve is sending water to heating via A, if I disconnect the 3 way valve it directs hot water to B which is connected to DHW tank. I just turned the pump down as it was running full tilt and an alarm has come up, turned it back up and alarm reset. ?. My brain hurts.

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23 minutes ago, joe90 said:

 

Ha, oh no it’s not ?. ASHP is running, pump running, three way valve operating all ok BUT, the three way valve is sending water to heating via A, if I disconnect the 3 way valve it directs hot water to B which is connected to DHW tank. I just turned the pump down as it was running full tilt and an alarm has come up, turned it back up and alarm reset. ?. My brain hurts.

You probably can't reverse the way the valve works so swap the plumbing over.

 

Heat pumps do seem to demand a high rate of water flow. I had to fit a second external pump to mine to get enough flow rate, and I bought a flow meter so I could see what flow rate I was achieving.   Another stupid thing, nowhere in the installation manual does it actually tell you what the minimum flow rate is.

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I've found that our unit (essentially identical, with an integral Grundfos pump) works fine with the pump on the low or middle setting, but gives an "over-pressure" alarm on the high setting, even with the (admittedly 1/2") bypass valve in place.  They don't seem to like running into a system with any significant flow restriction, but they only sense this indirectly by measuring flow back-pressure, rather than flow rate.

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2 hours ago, PeterW said:

Is the head on the right way round ..??? A B is correct as stated - or is as per a Danfoss one I’m looking at ..!

.

the head was fitted when I received it, it’s a Danfoss, it does appear the plumber installed it the wrong way round, can this be corrected by reversing the head or do I have to drain it down and swop the plumbing over?

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8 minutes ago, joe90 said:

.

the head was fitted when I received it, it’s a Danfoss, it does appear the plumber installed it the wrong way round, can this be corrected by reversing the head or do I have to drain it down and swop the plumbing over?

Was it never working properly before the ‘incident’ with the thermostat?

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3 minutes ago, Gav_P said:

Was it never working properly before the ‘incident’ with the thermostat?

 

No, blew it up connecting the remote room stat cuz I had duff info from the supplier ?

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8 minutes ago, Gav_P said:

Oh dear... well if it turns out you need a new 3 port valve (if it’s not just as simple as turning it around)  I have a spare one that came with the installation kit that I didn’t use. 

Thanks, it works, just the wrong way round and I don’t want to drain it down unless I have too.

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Okay an off the wall suggestion.

 

If it works, but is the wrong way round you, could switch a relay with the valve output from the heat pump, then use the NC contact on the relay to energise the valve, so the valve would be on, when the HP output is off, and vice versa.

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3 hours ago, JSHarris said:

even with the (admittedly 1/2") bypass valve in place.

 

My plumber did not instal a bypass, I have put them on “ordinary” heat systems in the past. If I remember @ProDave had a problem with his bypass the way it was installed!!!. Is it a good idea to fit one? Especially if I have to drain the system down to sort the 3 way valve. I would rather drain it down than introduce more relays etc .

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Yes indeed. If you fit an automatic bypass valve do NOT plumb it close to an elbow, better still do NOT plumb it in between 2 elbows.

 

Assuming the 3 port valve is mot the lowest item in the system you won't have to drain it all. I did not have to drain much at all to sort the ABV.

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None of the diagrams for my ASHP show a bypass valve and I cannot find a reference to one within the ASHP. As I have a diverter valve not two two way valves there should be no time that flow restriction will occur?. Answers on a post card to.........

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