Hello
I have an original (may be Mark1) Grant Combi 90 oil fired boiler that is overheating my hot water and central heating.
Recently I have changed the Auto bleed valve, the tank filler loop non return valve, the vessel and the thermostat.
Just to repeat I have changed the control thermostat.
The boiler, to my surprise, has two thermocouples in the recess in the tank at the rear of the boiler.
One goes to the control thermostat at the front of the control panel.
the second goes to a "valve" at the top of the boiler with an adjuster.
However my question is why is the water too hot and uncontrollable.
is it to do with the valve thing?
I have an original (may be Mark1) Grant Combi 90 oil fired boiler that is overheating my hot water and central heating.
Recently I have changed the Auto bleed valve, the tank filler loop non return valve, the vessel and the thermostat.
Just to repeat I have changed the control thermostat.
The boiler, to my surprise, has two thermocouples in the recess in the tank at the rear of the boiler.
One goes to the control thermostat at the front of the control panel.
the second goes to a "valve" at the top of the boiler with an adjuster.
However my question is why is the water too hot and uncontrollable.
is it to do with the valve thing?