Have checked the pump and it is spinning fine and when in HW only and HW and CH the flow is fine so I am guessing the pump is ok
Lots of hot water but no central heating
- Thread starter Starmatt
- Start date
Yesterday I spent some more time on this but this time I managed to borrow an infrared thermometer.
I also swapped over the actuator on the 3 port mid position valve for the new one I hade to rule that out. I also checked the wiring again and managed to override via the wiring the stats etc so pretty convinced it is not a wiring issue.
I set the Boiler thermostat to Max, put HW and CH on at the programmer. I then with the actuator removed from the valve I put the system into the HW position with the programmer on and the cylinder stat calling for heat and the pipe work temperatures at the boiler flow, pump and valve were around 42 degrees
I then manually moved the valve to the mid position and again all the temps at the boiler flow, pump and valve were around 42 degrees and as is the norm the rad's all got hot with the TRV's fully open as well as the lockshields.
I then moved the valve to the CH only position and within seconds the boiler flow and pipework around the pump and valve dropped to 28-30 degrees. The pump kept running and there was 240v at the boiler (there is no switched live to the boiler just the live that is also connected to the pump)
NOW - when I moved the valve slightly from the CH only position back towards mid within 2 seconds the pipework temp increased back to around 42 degrees and all rad's got hot quickly
I am thinking that if this were a blockage or flow issue then this heat increase would be more gradual than this as well as the rad's warming up - am I right in this assumption as the heat increase and decrease is dramatic?
I was then thinking could it be a control issue in the boiler - thermocouple, gas valve but the boiler only has one main thermocouple (it has a seperate one for the pilot light) and surely if this were faulty or the gas valve there would be issues when on HW only and HW/CH only - am I correct in this assumption?
If it were piped incorrectly would I see this sort of behaviour?
Hope this may throw some more light onto the issue for anyone out there would may be able to solve this mystery
I also swapped over the actuator on the 3 port mid position valve for the new one I hade to rule that out. I also checked the wiring again and managed to override via the wiring the stats etc so pretty convinced it is not a wiring issue.
I set the Boiler thermostat to Max, put HW and CH on at the programmer. I then with the actuator removed from the valve I put the system into the HW position with the programmer on and the cylinder stat calling for heat and the pipe work temperatures at the boiler flow, pump and valve were around 42 degrees
I then manually moved the valve to the mid position and again all the temps at the boiler flow, pump and valve were around 42 degrees and as is the norm the rad's all got hot with the TRV's fully open as well as the lockshields.
I then moved the valve to the CH only position and within seconds the boiler flow and pipework around the pump and valve dropped to 28-30 degrees. The pump kept running and there was 240v at the boiler (there is no switched live to the boiler just the live that is also connected to the pump)
NOW - when I moved the valve slightly from the CH only position back towards mid within 2 seconds the pipework temp increased back to around 42 degrees and all rad's got hot quickly
I am thinking that if this were a blockage or flow issue then this heat increase would be more gradual than this as well as the rad's warming up - am I right in this assumption as the heat increase and decrease is dramatic?
I was then thinking could it be a control issue in the boiler - thermocouple, gas valve but the boiler only has one main thermocouple (it has a seperate one for the pilot light) and surely if this were faulty or the gas valve there would be issues when on HW only and HW/CH only - am I correct in this assumption?
If it were piped incorrectly would I see this sort of behaviour?
Hope this may throw some more light onto the issue for anyone out there would may be able to solve this mystery
How did you move valve to CH position?
An IR thermostat is not very good good for heating matters. You need a contact type.
Temperatures at the boiler flow and return pipes are more relevant.
Did it suddenly stop working?
You seem to have no flow!
What is colour of water in system?
Tony
An IR thermostat is not very good good for heating matters. You need a contact type.
Temperatures at the boiler flow and return pipes are more relevant.
Did it suddenly stop working?
You seem to have no flow!
What is colour of water in system?
Tony
Set the programmer to HW and CH both being on and then turned the room stat up to max, the actuator was off the valve body but did move to the correct position and then I moved the valve spindle to the CH only position by hand.
It is hard to say if it suddenly stopped working as when we moved in the boiler was low and the cylinder temp on max and it was like this for a while and then as I say we had taps fitted that required the temp to be no hotter than 65 degrees. When the stat was turned down on the cylinder the issues started and then the last really cold winter we had 3 years ago I turned up the boiler temp and we were finding in a morning once the cylinder was up to 65 degrees the heating went cool and we woke to a cold house.
If it were a flow issue would the heat in the system become available so quickly?
When the system was drained the water was dark brown/black in colour but has been run for 6 hours with X800 in the system then drained and flushed.
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