Hi everyone. sorry for long post. I have a bit of a strange issue with my boiler. Had my boiler installed in jan 2012 and has always been running very well. Lately I Had an issue with my boiler pressure going over 2 bar and then going down below 0.6 bar when system cools. I drained the boiler down to 0 bar and then inflated the expansion vessel up to 1 bar and then boiler pressure went up so I drained boiler again an pumped up vessel to 1.1 bar. I usually open up all my trvs when topping up system to get flow running good and remove air. (I have 9 radiators mostly double, 1 rad does not have any trvs and has temp set to max and acts as a kind of release valve, even though boiler has a bypass built in). On this occasionI forgot to open all my trvs to max. boiler had circulation error light (probably had air on system) eventually managed to get air out by keep on resting boiler and allowing it to cool for a while in between. ( I have a spirotech rv1 and Magnaclean pro 2 near my boiler which I put in myself. Both have been in for at least 3 years and Magnaclean usually quite clean). Boiler then overheated and gave me overheat error. I later opened the trvs and got system running. No matter how high stat is set (it's Honeywell and I never had any issues with it ) the boiler starts up and the temperature lights go up quickly on the display and within a couple of mins the flame goes out (no overheating) the boiler has to stop for a few mins and then
Start up again. Hot water is ok unless I put temp at max and then that's starts to cut out. I replaced the temp probes in the boiler ( 1 had melted a bit)but problem didn't go. Tested new temperature probes with a multimeter and it was ok. I sent for an engineer and he tested various parts of the boiler and could not find any issue. he was blaming it on my pipework and told me I has a blockage as supply from boiler was very hot and return was quite cold bit I told him I never had any problems wity anything and it's been fine for years. He told my set-up puts a lot a load for boiler as boiler is in attic of house and most of the 3 bed house is 15mm pipework. After some discussion with him he did admit it could be pump however he could hear it vibrating normally and not making any strange noise. After he left I did notice pump head was very hot the touch. I can't find any way to switch speeds manually on pump as schematic in manual does not show any detail for the electrics so connection To pump (I am very competent in electrics as I used to be an electrician , can do basic plumbing using compression fittings and I never go near gas or combustion areas of a boiler). It's a wilo pump with special electrics fittings for the boiler. could not get any downloads for pump of the boiler. thinking of draining boiler and getting pump out and pulling it apart to look at impeller. I'm worried I might break it and maybe it's not faulty. 1 more thing boiler is quieter than normal I think it's because fan is not kicking in at full speed due to boiler not running much.
Start up again. Hot water is ok unless I put temp at max and then that's starts to cut out. I replaced the temp probes in the boiler ( 1 had melted a bit)but problem didn't go. Tested new temperature probes with a multimeter and it was ok. I sent for an engineer and he tested various parts of the boiler and could not find any issue. he was blaming it on my pipework and told me I has a blockage as supply from boiler was very hot and return was quite cold bit I told him I never had any problems wity anything and it's been fine for years. He told my set-up puts a lot a load for boiler as boiler is in attic of house and most of the 3 bed house is 15mm pipework. After some discussion with him he did admit it could be pump however he could hear it vibrating normally and not making any strange noise. After he left I did notice pump head was very hot the touch. I can't find any way to switch speeds manually on pump as schematic in manual does not show any detail for the electrics so connection To pump (I am very competent in electrics as I used to be an electrician , can do basic plumbing using compression fittings and I never go near gas or combustion areas of a boiler). It's a wilo pump with special electrics fittings for the boiler. could not get any downloads for pump of the boiler. thinking of draining boiler and getting pump out and pulling it apart to look at impeller. I'm worried I might break it and maybe it's not faulty. 1 more thing boiler is quieter than normal I think it's because fan is not kicking in at full speed due to boiler not running much.
