Hi Guys
I have a Vaillant 282eh boiler about 15 years old . It has over its lifetime had a new DHW exchanger,Main heat exchanger, DHW control valve, and just recently a new Diverter valve. It gets alot of use and I have been reasonably pleased with its performance.
I have a problem of the boiler heating up and cutting out due to the CH overheat Stat cutting in. This appears to be a result of poor CH circulation as radiators are not heating properly and following normal diagnosis would suggest a pump flow problem. The pump is running fine which led me to examine the gas operator modulation (it uses a diaphragm pump system to modulate gas flow). I can modulate gas flow by blowing into the air control line but I dont see any modulation of gas when system is operating normaly (green light on panel comes on okay suggesting diaphragm pump is ok).
DHW system works fine but again I dont see any gas modulation when water flow rate is reduced
I cannot understand why the circulation is poor as the system is clean. I noticed though that there is a system bypass valve shown on the VCW282 schematic. This valve is not mentioned in the fault finding and the CH bypass pipe work appears to link across under the boiler into the diverter valve. If it is leaking it could perhaps be my problem as it would short out the CH circuit causing rapid heating and if I have a gas modulation problem could lead to a rapid overheat
My question is , after all that rambling, is the system bypass valve a function of the diverter valve operation ? Is it possible that the diverter valve is dumping CH water through the bypass pipe?
thanks for any info
I have a Vaillant 282eh boiler about 15 years old . It has over its lifetime had a new DHW exchanger,Main heat exchanger, DHW control valve, and just recently a new Diverter valve. It gets alot of use and I have been reasonably pleased with its performance.
I have a problem of the boiler heating up and cutting out due to the CH overheat Stat cutting in. This appears to be a result of poor CH circulation as radiators are not heating properly and following normal diagnosis would suggest a pump flow problem. The pump is running fine which led me to examine the gas operator modulation (it uses a diaphragm pump system to modulate gas flow). I can modulate gas flow by blowing into the air control line but I dont see any modulation of gas when system is operating normaly (green light on panel comes on okay suggesting diaphragm pump is ok).
DHW system works fine but again I dont see any gas modulation when water flow rate is reduced
I cannot understand why the circulation is poor as the system is clean. I noticed though that there is a system bypass valve shown on the VCW282 schematic. This valve is not mentioned in the fault finding and the CH bypass pipe work appears to link across under the boiler into the diverter valve. If it is leaking it could perhaps be my problem as it would short out the CH circuit causing rapid heating and if I have a gas modulation problem could lead to a rapid overheat
My question is , after all that rambling, is the system bypass valve a function of the diverter valve operation ? Is it possible that the diverter valve is dumping CH water through the bypass pipe?
thanks for any info