Limiting DHW output of a glow worm Swiftflow 125E

[Ian Smith]

Hi all, I have a Swiftflow 125e glow worm boiler which Supplies bucketfuls of steaming hot water in the winter but during the summer it can be too hot. There is a potentiometer on the control board that can be used to limit the burner gas pressure. Would it have an adverse effect if I reduced this setting to limit the heat output of the burner. I am hoping this would safely turn my boiler from a 125,000 btu to a

100,000 btu unit or less for the summer months then allow me to turn it up again in the winter. any advice from someone with experience in this area would be much appreciated.

cheers ian

[BigWallop]

Does it have wires coming from it ? Or is there just a single stiff tube like thing coming from it ?

If it has wires coming from it, then it's called a rheostat and it is meant to be used to vary the heat output from the boiler by varying timed impulses to the burner ignition unit.

If it has a single stiff tube like thing coming from it, then it is called a couple thermostat, and it is used to vary the heat output from the boiler by reducing the electrical conductivity through the thin carbonised tube and make a clean open circuit to the boiler ignition unit.

[Christian McArdle]

If there is no thermostat for the outgoing water you should fit a thermostatic mixing valve on the water outlet. It might provoke more cycling on the boiler, though, if the (presumably) modulating burner won't go low enough. Alternatively, turn the tap on higher.

I wouldn't play with the gas controls.

Christian.