Hi All,
Long time reader, but not a regular poster.
I have a strange problem with my CH/HW setup. First I will list the parts.
Glowworm Boiler
Danfoss Electronic Timer with separate water and heating functions - 7 day programmable.
Cylinder Stat
Danfoss RX-1 room thermostat (all working fine red light on when stat is calling for heat, red light off when not, audible click between on and off)
Danfoss HSA3 3 port valve (recently replaced actuator head due to rads heating up when HW only was on)
When I say strange I mean in it's occurance.
I have the HW and CH set to come on at 6am. The HW is scheduled to go off at 6:40am the CH continues through until 8am.
At 6am both the HW and CH works. The rads get hot and the cylinder warms up.
At 6:40 the HW goes off and the CH (if the room stat is calling for heat) continues to work.
At some point around 7am the room stat is satisfied and the CH goes off.
It's at this stage something strange happens when the room stat calls for CH again.
The light on the timer is on to call for CH.
The light on the RX1 is on to call for CH.
The boiler does not fire.
If I turn the room stat down and back up again the RX1 light goes off and comes on again as it should and yet still no boiler firing.
If I leave the Controller CH call to on and turn on the HW on the controller the boiler fires (I've had a shower inbetween times and so the Cylinder stat is calling for hot water).
If I turn the HW off at the controller the boiler should still fire as the room stat and controller are asking for CH. This does not happen.
To get the CH to work again I have to turn off the call for CH at the controller. Turn on the HW at the controller again. Turn off the HW at the controller and then turn on the CH at the controller. This then allows the boiler to fire and the rads warm up.
Subsequent calls from the room stat stop and start the boiler as normal.
This has happened every morning for the past week.
However, in the evening I have the exact same timing arrangement but for CH for longer.
7pm both CH and HW come on.
HW goes off at 7:40pm.
The CH goes on until 11pm and works fine with the room stat doing the job of controlling the boiler firing depending on temperatures.
So, I am going to open up the wiring centre when I get a chance to see what is happening (first diagram here http://danfoss-randall.co.uk/PCMPDF/39917v05.pdf). I believe there is an issue with the 3 port valve but I'm not sure what. I don't think it is a mechanical issue as I would expect heating to be on when HW is called for or HW to be heated when CH is called for but I dont believe this to be the case.
Therefore is it something electrical? If so what?
As I will have to look at the wiring centre first thing in the morning I'd like to narrow down what I'm looking for in advance and get it straight in my head.
Any pointers gratefully received.
Thanks
Craig
Long time reader, but not a regular poster.
I have a strange problem with my CH/HW setup. First I will list the parts.
Glowworm Boiler
Danfoss Electronic Timer with separate water and heating functions - 7 day programmable.
Cylinder Stat
Danfoss RX-1 room thermostat (all working fine red light on when stat is calling for heat, red light off when not, audible click between on and off)
Danfoss HSA3 3 port valve (recently replaced actuator head due to rads heating up when HW only was on)
When I say strange I mean in it's occurance.
I have the HW and CH set to come on at 6am. The HW is scheduled to go off at 6:40am the CH continues through until 8am.
At 6am both the HW and CH works. The rads get hot and the cylinder warms up.
At 6:40 the HW goes off and the CH (if the room stat is calling for heat) continues to work.
At some point around 7am the room stat is satisfied and the CH goes off.
It's at this stage something strange happens when the room stat calls for CH again.
The light on the timer is on to call for CH.
The light on the RX1 is on to call for CH.
The boiler does not fire.
If I turn the room stat down and back up again the RX1 light goes off and comes on again as it should and yet still no boiler firing.
If I leave the Controller CH call to on and turn on the HW on the controller the boiler fires (I've had a shower inbetween times and so the Cylinder stat is calling for hot water).
If I turn the HW off at the controller the boiler should still fire as the room stat and controller are asking for CH. This does not happen.
To get the CH to work again I have to turn off the call for CH at the controller. Turn on the HW at the controller again. Turn off the HW at the controller and then turn on the CH at the controller. This then allows the boiler to fire and the rads warm up.
Subsequent calls from the room stat stop and start the boiler as normal.
This has happened every morning for the past week.
However, in the evening I have the exact same timing arrangement but for CH for longer.
7pm both CH and HW come on.
HW goes off at 7:40pm.
The CH goes on until 11pm and works fine with the room stat doing the job of controlling the boiler firing depending on temperatures.
So, I am going to open up the wiring centre when I get a chance to see what is happening (first diagram here http://danfoss-randall.co.uk/PCMPDF/39917v05.pdf). I believe there is an issue with the 3 port valve but I'm not sure what. I don't think it is a mechanical issue as I would expect heating to be on when HW is called for or HW to be heated when CH is called for but I dont believe this to be the case.
Therefore is it something electrical? If so what?
As I will have to look at the wiring centre first thing in the morning I'd like to narrow down what I'm looking for in advance and get it straight in my head.
Any pointers gratefully received.
Thanks
Craig