Problems with Firemaster High Output Boiler

[JonnyMcN]

My friend has a firemaster high output boiler in his house and is having some problems with it. Hopefully someone can help.

Once fire is lit and is hot enough the circulating pump is turned on to supply heat to the radiators.

After lighting the fire today, the radiators were hot for about an hour but then went cold. You can still hear the water circulating around the radiators but no heat just barely luke warm even with a raging fire.

Sorry to start a new topic on the same page but might as well try to see if both problems are linked.

They have a Rayburn PJ cooker range which runs on oil. When it is on it struggles to heat all the radiators to the correct temperature. But if you turn the thermostat on the left hand side of the range up to about 50/55 they heat up to the correct temperature. The only problem with adjusting the thermostat like this causes the range to boil and does not cut off when it reaches the correct temperature.

All comments and advice are greatly appreciated.

 

[oilhead]

Not familiar with the Firemaster range, but problem with the PJ sounds like circultaion problems. Setting the thermostat to 50/55 means the temperature of the water in the rads should only be this. If this causes the boiler to kettle, then there is either poor circulation through a faulty pump or obstructed pipework, or the boiler is heavily scaled. If the boiler gets too hot, then the pump overun thermostat should cut out the burner until it cools down. This can be a problem if the cooker is in use.
Also, what firebricks are in use in the combustion chamber? If still the summer bricks, then the kettling may be localised but insufficient volume to heat the rads.

 

[JonnyMcN]

The fire master fire back boiler is basically the same layout as a grant triple pass back boiler if that helps with draught damper at the top of the fire appliance.

I am not a plumber by any standard but just want to localise the problem before any high costs occur.

The Rayburn range has never done this before??

Also the heating controls that are being used for this dual heating system is horstmann 425 diadem. What position should the controls/pull down switches be when he has a fire lit and wants to use the back boiler via a circulating pump beside the fire itself.

Thank you for reply, all comments and advice are appreciated

 

[oilhead]

Without being there to examine the integration of controls, sorry I cannot help. Many short cuts are taken in such circumstances; control of dual circuits is not easily done on the cheap. Much needs to be automatic and cannot be controlled closely.