Interestsing about the cpacitor. It must be lowcapacitancerather than open cicuit so there was enough torque to turn the motor and fan but not whith the much higher load of the fuel pump.
However this is now all a bit strange!
What figures does the manufacturers manul say? (and what boiler is it?)
Is the combustion gas path through the baffles and out of the flue clear?
Is it a balanced flue? If so try disconnecting the air inlet tube.
Thanks for your continued interest in the saga.
The boiler is a Benson Jetstream series 3(Conventional Flue)- 69,000btu(50/70),with believe it or not quotes a rated oil pressure on kerosene of 150 psi with a Danfoss 0.65 80ES jet(although the spec called for Delevan 0.65 80W). The pressure is supprising since the spec also lists gas oil at 125psi in complete contradiction of which is normally used on high pressure(gas oil)
The boiler is 15 years old.
More supprising is Bensons Jetsteam series 4 which for the same rating boiler lists oil pressure at 110psi with a Danfoss nozzle 0.60 80H, and details the net flue temperature at 197C.(conventional flue)
All a mystery to me but the series 3 spec lacks the detail for the series 4.
Since the boiler has run quite well although noisy the subject of settings only came up in discussions with Riello on best settings. Apparently the calorific value of Kerosene has change somewhat from when the boiler was manufactured.
It was suggested a Danfoss 0.60 80Es nozzle be fitted and the oil pressure
set to somewhere between 8/9bars(120-130psi) and adjust air slide to give 12,5 %CO2.
This has not been achieved and the best result has been 110psi at 11.5%CO2. However the stack temperature is a lot higher at 250C which is worrying since Riello quoted 200-225C and near the figure achieved using the 0.65 jet. A test was also carried out to check the smoke and again was bordering on calling for more air which would have increased the outlet temperature.
It has been left that after a week I examine the baffles and boiler internals and report condition. Also do a further analysis of temperature etc.
The radiators appear to be heating up ok and not too many firings of the boiler. Have room stat set at 20c like before. We only have 5 radiators on the system including the bathroom, I calculated these having about 20,000btu,s plus hot water cylinder plus cottage with stone walls and double glazing.
You further comments welcomed.
Hood