worcester 4.5 BF Boiler

[James Bryan]

I am having problems with the hot water overheating.on aWorcester 4.5 balanced flue boiler. It is ok when on water only but the central heating pump is running even when it is switched to hotwater only. When should the mid-port valve be energised (a) to meet the demand for hotwater or (b) to meet the demand for heating. The system is open vented on the heating.

Any information you may be able to give me would be very much appreciated.

Jim Bryan

 

[Agile]

Jim, I am not familiar with your model and as no one else has replied I dont think others are either!

I am guessing thats its a heat only boiler and not a combi?

If you have a seperate mid position valve then I dont think that you can understand its operation. Its motor is powered in two of its three positions.

On the simplest situation if the hot water in a cylinder is overheating then the prime suspect at first will be the cylinder stat.

Can you describe the boiler function in more detail please?

Tony Glazier

 

[Gasman1015]

It is a floor standing storage combi, the valve rests in hot water mode and is energised for heating, which is controlled by a plug in relay in the control box.

 

[Agile]

Sounds like a forerunner to the 400 then.

You seem to have answered your own question.

I would expect the pump to be running all the time the boiler is firing and the diverter to be powered when the hot water has been preheated to the set temperature and the heating selected.

I am not quite sure what the problem is. If its not switching to heating it could be because the hot water storage thermostat is not becoming satisfied probably because its faulty?

Tony Glazier

 

[Gasman1015]

I am having problems with the hot water overheating.on aWorcester 4.5 balanced flue boiler. It is ok when on water only

Maybe you can tell us what the problem is, if it overheats on this model in normally shuts down the pilot light, is this the case.