PeterW Posted February 12, 2018 Share Posted February 12, 2018 Lever on the right is the manual override. HSA3ND is a a simple diverter head with no microswitch. Need to have a look at what is actually triggering that heat pump to fire ..! Link to comment Share on other sites More sharing options...
Lynford Posted February 13, 2018 Author Share Posted February 13, 2018 Right, ta. Would the trigger for the unit not come from the room stat / timer ? I’m afraid all this is a bit beyond me. Link to comment Share on other sites More sharing options...
Jeremy Harris Posted February 13, 2018 Share Posted February 13, 2018 40 minutes ago, Lynford said: Right, ta. Would the trigger for the unit not come from the room stat / timer ? I’m afraid all this is a bit beyond me. The unit needs a switch that is not connected electrically to anything else wired between terminals 3 and 6 on the heat pump unit to turn it on. In order for the heat pump to operate in heating (rather than cooling) mode terminals 3 and 7 must be bridged too. These terminal numbers refer to the terminal block outside in the heat pump. They are at 12V on an isolated supply, so just a switch across 3 and 6 will turn the heat pump on and off. Often there will be a microswitch on a motorised valve that operates when the valve moves and can be used to turn on the heating. If it is wired as per the diagram in the manual, then terminals 3 and 6 should be wired directly to the thermostat and the thermostat then turns the heat pump on and off. According to that diagram, the thermostat is the only on/off control for the heat pump. You should be able to check whether or not it turns the heat pump on and off by adjusting the thermostat temperature upwards and seeing if the heat pump comes on. You will probably hear a click in the thermostat as it goes above the set point. If you hear the thermostat operate, but the heat pump does not turn on, then that indicates a problem somewhere with the low voltage wiring between the thermostat and the external unit. You can bypass the thermostat (with the external cover of the heat pump removed, (bearing in mind the caution about there being live connections exposed) by connecting a bit of wire between terminals 3 and 6, making sure terminals 3 and 7 are linked. Doing this is safe, as those terminals only have at most 12 V on them, Link to comment Share on other sites More sharing options...
Lynford Posted February 13, 2018 Author Share Posted February 13, 2018 That’s brilliant, thank you. This gives me a few things to try / check. As I said before, I’ll take some bootlace ferrules up next time and tidy all that messy wiring in the pump. Some of the connections didn’t look great, maybe a wire slightly hanging out / not done up properly could be at fault ? I can check that 3&7 are linked together, and if necessary link out 3&6 to try and start the pump. Also if I take my meter up, using a length of cable I can bell out the wire between the unit and the wiring insdoors to make sure all is well there. Thanks again Jeremy Link to comment Share on other sites More sharing options...
Jeremy Harris Posted February 13, 2018 Share Posted February 13, 2018 As a couple of further points, the heat pump has internal 230V AC relays that are used normally to switch on the heating circulation pump and operate the three way valve, to select between heating and hot water. The heat pump will turn on in hot water mode if terminals 13 and 15 are connected, via the programmer and tank thermostat. When the heat pump switches to hot water mode, the circulation pump for the heating will probably be turned off and the motorised valve should switch to the hot water position. If you look at the wiring diagram in the manual, on page 19, you can see that there are another set of no-volt switches connected to terminals 13 and 15, the tank thermostat and programmer, which look to be wired in series. This means that in order to get hot water, both the time switch contacts must be closed and the tank thermostat contacts must be closed. Hot water mode over-rides heating mode completely, so if the unit is being asked to deliver hot water it won't run the heating. Worth checking those as well - they are no-volt connections, so should be a maximum of 12 V. The operating sequence in heating mode is that the room thermostat calls for heat (the contacts close that should be connected to terminals 3 and 6) and as long as there is not a call for hot water (in other words either, or both, the timer or the tank thermostat contacts are open) then the heat pump should turn on the circulating pump, ensure that the motorised valve is in the heating position and then the heat pumps should start running. It has a slow ramp up, and takes around 30 seconds to start up, as it has a designed in soft start. Link to comment Share on other sites More sharing options...
PeterW Posted February 13, 2018 Share Posted February 13, 2018 I’m wondering if this is stuck in DHW mode and the diverter is jammed. If it’s W plan then priority is hot water, but unless the tank is satisfied then heating will never come on. Wired wrongly, and with the temp set too high on the tank stat, it will never satisfy the DHW need and never go to heating mode. @Lynford when was the tank replaced ..? And out of interest, what’s the rough location of the in-laws..?? Link to comment Share on other sites More sharing options...
Jeremy Harris Posted February 13, 2018 Share Posted February 13, 2018 The heating circulating pump will come on, as will the heat pump, even if the valve is jammed. The pump and the valve are controlled by relays inside the heat pump. As long as terminals 13 and 15 are open circuit, and as long as terminals 3 and 6 are closed, the heat pump will run in heating mode and the circulating pump will come on. Link to comment Share on other sites More sharing options...
Lynford Posted February 16, 2018 Author Share Posted February 16, 2018 On 13/02/2018 at 19:38, PeterW said: I’m wondering if this is stuck in DHW mode and the diverter is jammed. If it’s W plan then priority is hot water, but unless the tank is satisfied then heating will never come on. Wired wrongly, and with the temp set too high on the tank stat, it will never satisfy the DHW need and never go to heating mode. @Lynford when was the tank replaced ..? And out of interest, what’s the rough location of the in-laws..?? Hello Peter, The tank was was replaced a couple of months ago, but the system has never really run properly (certainly not when it’s cold outside). It’s hard to work out from the information I have if it’s better or worse since. It’s pretty much turned off now with the immersion doing the HW and a plethora of electric heaters heating the bungalow, which I imagine is making the electricity meter whirr like a good un. They live in a village in Norfolk, near Brandon. Going back up there tomorrow to tidy up some of the wiring, and try a few things suggested on here. I’ll make sure to check the diverter. Cheers. Link to comment Share on other sites More sharing options...
Lynford Posted February 16, 2018 Author Share Posted February 16, 2018 On 13/02/2018 at 19:47, JSHarris said: The heating circulating pump will come on, as will the heat pump, even if the valve is jammed. The pump and the valve are controlled by relays inside the heat pump. As long as terminals 13 and 15 are open circuit, and as long as terminals 3 and 6 are closed, the heat pump will run in heating mode and the circulating pump will come on. Just to to be clear Jeremy, these are the terminals within the actual heat pump ? So I can check that 13 & 15 are open with my meter, link out 3&6 and I should be getting heating ? Ta, Lyndon Link to comment Share on other sites More sharing options...
Jeremy Harris Posted February 16, 2018 Share Posted February 16, 2018 1 hour ago, Lynford said: Just to to be clear Jeremy, these are the terminals within the actual heat pump ? So I can check that 13 & 15 are open with my meter, link out 3&6 and I should be getting heating ? Ta, Lyndon Yes, these are the terminal numbers inside the heat pump itself. take care, as there are low voltage (12V DC) terminals that are pretty close to some that may have mains voltage on. Just as you say, if you ensure that 13 and 15 are open, that 3 and 6 are linked and that there is also a link from 3 to 7 (that puts the heat pump into heating mode, if terminal 7 is not linked to terminal 3 the heat pump will run in cooling mode). Hope this helps. Link to comment Share on other sites More sharing options...
Lynford Posted February 16, 2018 Author Share Posted February 16, 2018 Brilliant, ta. Yeah I saw the mains terminals, no sign of any attempt to keep them covered up really is there ! Hopefully I can find something out tomorrow. Cheers. Link to comment Share on other sites More sharing options...
Lynford Posted February 17, 2018 Author Share Posted February 17, 2018 Afternoon all, So today feels a little one step forward, two steps back. I went to fit bootlaces to the wires but took the wrong size (not sure I could get more than one of any size in a terminal anyway) Checking the connections, I found that #3 wasn’t done up properly. I went to tighten it and found out why - It’s broken (see pic 1, you can see the screw isn’t done up properly, because it can’t be). As per Jeremy’s tips, if 3&7 are linked out the unit tries to cool. So I’m thinking, “this is it, job done” With no no other means of fixing it, I’ve put a chocolate block in between the three wires in terminal 3, and the other side of the terminal (see pic 2). I’m hoping that there isn’t another internal link from the terminal block that I can’t see. So all connected up, the ASHP starts running and after a short while I feel heat on the flow side. Nothing getting to the rads, so bearing in mind Peter’s thoughts about the diverter valve, I flicked over the manual lever.........and I get heat at the rads. WOO HOO. Obviously not in the clear here, still need it to check I can produce HW and there’s the confusion / issue with the diverter valve but feeling pretty smug. UNTIL The Rads didn’t seem to be heating anymore, so I go outside and the ASHP isn’t running. Inside the unit on the PCB where Jeremy got me to check last week, I had 3 lights on. The one I had last week in green but two above it in amber (D802 & D804, picture 3) Also a flashing red LED on a lower board, that I don’t remember from last week. Nothing on the Kingspan diagnostic box. I checked that 3&6 were still closed, so telling the pump to run. A lot of (garbled) info there chaps........any ideas where I go from here please ? Cheers, Lyndon Link to comment Share on other sites More sharing options...
Jeremy Harris Posted February 17, 2018 Share Posted February 17, 2018 I'm struggling through this, as the LEDs don't seem to match those for the KHP 0040 12kW version. From the manual, if there are LEDs marked above D803, then it looks as if the control board is a KHP0042. According to the Kingspan info, then when LEDs D802 and D804 are illuminated, that indicates "high pressure protective operation" (D805 is the "on" LED). This relates to the flow pressure, I think, as mine does this (but displays the info more meaningfully on the Command Unit) when the flow is restricted. The only way that can happen is if something like a valve has closed which has restricted flow enough to trip the over-pressure sensor. It should try to start again after a few minutes, but if the flow restriction is still there it will shut down again. The flashing red LED is the internal diagnostic code LED, and will flash at 1/2 Hz when everything is OK, but will give a flash sequence that can be counted if something has gone wrong in the heat pump. If it's just flashing regularly then there is no fault. Terminal 3 is the 12 V ground terminal, and is replicated on other terminals on the block. According the the info I have, terminal 3 is also connected internally to terminal 13, both are 12 V ground terminals, so if terminal 3 is broken you could use terminal 13 as a substitute. So, it looks like what has happened is that the unit has fired up, the rads have heated up, but something has shut down the rads and caused the flow pressure to rise and trip the heat pump off. The next bit of sleuthing is to find out what has caused the rads to turn off. Do they have thermostatic valves? If so, then one possibility is that they have closed down as the rooms temperature has increased. If they don't, then we need to have a look to see what else could be causing the flow to shut down. Link to comment Share on other sites More sharing options...
PeterW Posted February 17, 2018 Share Posted February 17, 2018 Makes me wonder if there is no auto bypass and there are TRVs everywhere ... Link to comment Share on other sites More sharing options...
Jeremy Harris Posted February 17, 2018 Share Posted February 17, 2018 10 minutes ago, PeterW said: Makes me wonder if there is no auto bypass and there are TRVs everywhere ... I wondered about that too. I had exactly this fault on mine when I first set it up, as the thermally actuated valve, that opens the flow to the manifold, took several minutes to open. The heat pump would fire up, sense the high pressure in the flow and then shut down with an error. It would keep re-trying every minute or two, until the valve had opened and then the error cleared. To fix it I had to drain the system down and fit a bypass, and since then it's been fine, although it took a bit of fiddling to set the bypass pressure to the right setting. Link to comment Share on other sites More sharing options...
PeterW Posted February 17, 2018 Share Posted February 17, 2018 I plan to use a diverter that will just swap from buffer to DHW coil in a reverse W Plan so I should never have a closed circuit however fitting one may be done for belt and braces ..! Link to comment Share on other sites More sharing options...
Lynford Posted February 17, 2018 Author Share Posted February 17, 2018 (edited) Hello gents, So I could have used #13 instead of bodging up modifying #3……I may revisit that next time I go up, ta. Yes there are TRVs on all of the rads - Should I be looking at opening these all up fully and trying it again ? There are also what look like filters in both the flow & return of the system, Maybe these could a restriction in flow and rise in pressure ? As ever, thank you. Edited February 17, 2018 by Lynford Link to comment Share on other sites More sharing options...
Lynford Posted February 17, 2018 Author Share Posted February 17, 2018 Filters ? Link to comment Share on other sites More sharing options...
PeterW Posted February 17, 2018 Share Posted February 17, 2018 Magnaclean and a Spirovent ..!! Thats impressive..! One or the other, don’t need both but they won’t restrict unless they are full of crud. Open all the TRvs to 5 and let it rip ... Link to comment Share on other sites More sharing options...
Jeremy Harris Posted February 17, 2018 Share Posted February 17, 2018 Just as @PeterW, says, just open all the TRVs, I'm pretty sure that's what caused the shutdown, as there doesn't seem to be a pressure bypass. Yes, you can use 13 instead of 3, as they are both connected electrically on the board to the 12 V ground. Once you have it working with the wire links and the TRVs open, then the next step is to determine why the thermostat doesn't fire it up. My recommendation would be to test it with the TRVs open and your wire links, if that works OK, then remove the wire links and reconnect it so the thermostat is controlling it, but leave the TRVs wide open. If that works, then you can adjust the TRVs, but make sure one of them is always fully open to act as a bypass, ideally one near the thermostat, perhaps. Link to comment Share on other sites More sharing options...
Lynford Posted February 17, 2018 Author Share Posted February 17, 2018 Again, thanks chaps. 34 minutes ago, PeterW said: Magnaclean and a Spirovent ..!! Thats impressive..! One or the other, don’t need both Oh yeah, it’s got everything Peter..........bar the ability to heat the place ! Link to comment Share on other sites More sharing options...
Lynford Posted February 17, 2018 Author Share Posted February 17, 2018 30 minutes ago, JSHarris said: Just as @PeterW, says, just open all the TRVs, I'm pretty sure that's what caused the shutdown, as there doesn't seem to be a pressure bypass. Yes, you can use 13 instead of 3, as they are both connected electrically on the board to the 12 V ground. Once you have it working with the wire links and the TRVs open, then the next step is to determine why the thermostat doesn't fire it up. My recommendation would be to test it with the TRVs open and your wire links, if that works OK, then remove the wire links and reconnect it so the thermostat is controlling it, but leave the TRVs wide open. If that works, then you can adjust the TRVs, but make sure one of them is always fully open to act as a bypass, ideally one near the thermostat, perhaps. Lovely, thanks chaps. We’ll see what happens with the TRVs open. I’ve had help on forums before but some of you people are different level. Cheers. Link to comment Share on other sites More sharing options...
Jeremy Harris Posted February 17, 2018 Share Posted February 17, 2018 Just now, Lynford said: Lovely, thanks chaps. We’ll see what happens with the TRVs open. I’ve had help on forums before but some of you people are different level. Cheers. Thanks, we try our best! Link to comment Share on other sites More sharing options...
Temp Posted February 17, 2018 Share Posted February 17, 2018 Check all the rads get some heat? I wonder if the system is full of crud because nobody put corrosion inhibitor in it? If it's not been used for a long time perhaps it's all settled out so it only takes one or two tvr to shut off to block the flow? Link to comment Share on other sites More sharing options...
Lynford Posted February 17, 2018 Author Share Posted February 17, 2018 6 minutes ago, Temp said: Check all the rads get some heat? I wonder if the system is full of crud because nobody put corrosion inhibitor in it? If it's not been used for a long time perhaps it's all settled out so it only takes one or two tvr to shut off to block the flow? All the rads appeared to be getting the same amount of heat. I think this has even been put in since they moved in, but I will ask. Cheers. Link to comment Share on other sites More sharing options...
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