I was away last week and came home to a cold house, where only two raditors upstairs were luke warm, the rest being cold. At that point the hot water was working ok.
I have a Potterton prima B gas boiler downstairs with a Danfoss FP975 controller, a hot water tank up stairs where the pump (Grudfoss 15/50) and two motorised valves (Danfoss HPA2) are and a header tank in the loft.
I tried bleeding all the radiotors to see if any air would come out - they seemed ok. (I tried this with the system on as well as off).
I checked the pump, it gets warm when switched on, I have also checked that the current is ok, it makes a very quite buzzing sound (I guess that must be normal).
I have two motorised valves next to the hot water tank, they both seem to work ok, the hot water opens when called for as does the other one when the raditors are called for.
When adjusting the main radiator thermostat the valves and pump switch on accoringling.
At this point I decided to drain the system (I have been in the house for 5 years and have not touched the radiors, although I had the gas boiler serviced about a year and a half ago). I switched off the gas and electrical supply to the system. Then stoped the mains water from filling the header tank in the loft. I opened up all the radiator thermostatic valves, then downstairs opened up the drain point on the radiator.
At first the water seemed clean but very quickly it became fairly black. I repeated this process once more as the water colour seemed to improve a bit.
I then filled the system to a point were the tank in the loft had a small amount of water in it. Then added some system cleaner (from Salamander, following their instructions - they say that this should remain in the system for approximatly 21 - 28 days before flushing out). I then topped up the tank in the loft.
Went around all the radiotrs to remove the air by opening the bleed valve at the top of each valve waiting for the water to flow out.
Then switched the electrical supply on so that the pump would run and re-checked for air in the radiators.
Once this was done I switched the gas boiler back on to find the system to be worse off as the both the hot water system and the radiators are not warming up.
Something I noticed is that when I switch the gas on, the gas boiler flairs up for about 1 to 2 minutes and then goes back to the pilot light regardless of the thermostat settings (which I can hear switch when I adjust them).
Do you have any suggestions as I think I am reaching the point where I need to call in the experts?
I have a Potterton prima B gas boiler downstairs with a Danfoss FP975 controller, a hot water tank up stairs where the pump (Grudfoss 15/50) and two motorised valves (Danfoss HPA2) are and a header tank in the loft.
I tried bleeding all the radiotors to see if any air would come out - they seemed ok. (I tried this with the system on as well as off).
I checked the pump, it gets warm when switched on, I have also checked that the current is ok, it makes a very quite buzzing sound (I guess that must be normal).
I have two motorised valves next to the hot water tank, they both seem to work ok, the hot water opens when called for as does the other one when the raditors are called for.
When adjusting the main radiator thermostat the valves and pump switch on accoringling.
At this point I decided to drain the system (I have been in the house for 5 years and have not touched the radiors, although I had the gas boiler serviced about a year and a half ago). I switched off the gas and electrical supply to the system. Then stoped the mains water from filling the header tank in the loft. I opened up all the radiator thermostatic valves, then downstairs opened up the drain point on the radiator.
At first the water seemed clean but very quickly it became fairly black. I repeated this process once more as the water colour seemed to improve a bit.
I then filled the system to a point were the tank in the loft had a small amount of water in it. Then added some system cleaner (from Salamander, following their instructions - they say that this should remain in the system for approximatly 21 - 28 days before flushing out). I then topped up the tank in the loft.
Went around all the radiotrs to remove the air by opening the bleed valve at the top of each valve waiting for the water to flow out.
Then switched the electrical supply on so that the pump would run and re-checked for air in the radiators.
Once this was done I switched the gas boiler back on to find the system to be worse off as the both the hot water system and the radiators are not warming up.
Something I noticed is that when I switch the gas on, the gas boiler flairs up for about 1 to 2 minutes and then goes back to the pilot light regardless of the thermostat settings (which I can hear switch when I adjust them).
Do you have any suggestions as I think I am reaching the point where I need to call in the experts?
