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It is yes
Discuss Air source heat pump heating issue in the Central Heating Systems area at ElectriciansForums.net
It is yesThe programmer you have, is it a Honeywell ST9400c ?
I did ask to see your controls in another post as I suspected that you had that programmer.
Turn off the demand for hot water and heating.
Turn the cylinder and room stats up to ensure they both call for heat. (make sure you turn the cylinder down again when you have tested the programmer)
Using the override buttons you should see the green lights and hear two distinct clicks. The sound of the clicks are the important bits, so listen for them both.
If you only hear one click then the programmer is at fault.
What is the make and model of the ASHP please?
Speed reading this thread did I pick up correctly:
1a. you have a hot water tank and separate buffer hot water tank?
1b. The buffer tank contains the heated water for the radiator circuit?
2. as far as you know the installation control is S plan or some derivative of it?
3. you have a room thermostat(s), a hot water tank thermostat and a buffer tank thermostat?
4. One pump.
Did the system ever work correctly?
What solenoid valves do you have and their type - just post a picture of the label on them or the part number and make.
Please draw a sketch of the valves, pump, ASHP, tanks, rads water circuit.
Re your #53 - is there a link between terminals 11 and 12? I cannot tell from the image.
Such a link seems to be required for simultaneous space and water heating according to the manual.
That's correct there is a stat on the buffer tank, all pumps and MVs work when heat is called for just not the heat pump.No don't do any measurements.
So the fault is that the ASHP will never run up in demand to a space thermostat to warm the water in the buffer tank?
Please confirm whether there is a 'stat on the buffer tank - I'd expect to see one.
The programmer does have HW and CH selected to on and either in a timed on period or sert to constant?
Thank you, please see added pic to above post of stat on HPI have enough now to be getting on with. I hope to reply tomorrow morning.
What I would suggest if you feel able and safe - is to do a quick wire change. Before you touch any wiring you must isolate all electricity and check afterwards it is dead - do know how to do that? The easiest way to isolate is switch off the home main switch/switches which is what I recommend you do.
What we are going to check is the operation of the 2 port Motorised Valve(2PMV) for the CH circuit and check that the water pump starts.
To do this we are going to disconnect the white wire at terminal 13 at the ASHP and label with tape or a marker pen or note the number on it so its purpose is not lost. Put its end in a connector block or WAGO and then move it of harm's way.
Now, remove the wire from terminal 10 and insert it into terminal 13 and tighten up.
Re-connect power.
Set the programmer to 'Constant HW' (or advance the switch on or press override for HW).
Next we need to create a demand for HW (yes HW) by running off from the HW tank or turning up the HW set temperature. The latter is the easiest and quickest but up to you how. Now go to the water pump and observe the green lights on it. When a HW demand is created does the water pump start? If it does, go and see of the ASHP starts - it may take a little while. If the ASHP starts wait a while and feel the radiators to see of they become warm. If the pump does not start, it may be the HW demand has not been signalled so run off some hot water to much reduce the tank water temperature. Unless a demand for HW is generated the test will not begin.
Turn the HW tank stat to its lowest set temperature, when the demand for HW ends, the water pump and ASHP should shut down.
That's the end of the test. So isolate electricity and return the white wires you removed to their original terminals.
I look forward to hearing the results. We are checking the external logic ' demand 2PMV(CH) opens and when opened start water pump', and the ASHP internal logic 'if circulant water flow detected and there is an >?? Celsius temperature difference between out and return then start ASHP'
I won't give any more explanation to avoid confusing you.
That's correct, i assume I connect terminals 11 and 12 on the junction box and not the heat pump?Re#76 - Ok. Don't do what I asked in #75 if you agree with this statement:
'When ONLY CH selected on the programmer (HW constant off) the 2pMV(CH) opens and the water pump starts when I increase the room stat to 30C and stops when I turn the room stat to 5C.'
If you agree with this statement then I would like you instead to link terminals 11 and 12 with a short piece of wire having first isolated electricity. Then see if the ASHP will come on (and rads warm up) with only CH selected on the programmer by turning room stat up to 30C.
Done as requested, nothing at the heat pumpVery good question - at the heat pump. I should have been much clearer :-(
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