Boiler problems...

[Miguel]

Hello

Was wondering if anybody could help me with my gas boiler. It seems to work fine during the summer when I am only using it for hot water, however has a nasty habit of 'tripping' when the central heating is on.

It is a Glow-worm Fuelsaver F, Fanned Flue boiler. The central heating is called something like a 'Closed ?? System. If I was to ever top up the water, I would have to open a water valve. I was told to keep the pressure at about 1.5bar.

When I say 'trips', the boiler itself trips and I have to press a button on the bottom to reset it. It happens anything between 1-3 times per week.

Any advice would be appreciated as I don't want to end up without a boiler this winter! If its a sign of bad things to come, I may have to make a sneeky call to scottish, or should I say British gas to insure my boiler :)

Thanks, Miguel

[Ed Sirett]

For some reason there is no flow through the boiler in CH mode.

This could easily be due to all the TRVs shut down (it's not actually very cold yet but it is colder than it was). The TRVs can also jam shut over the summer.

[Roger Mills]

It sounds like the boiler is over-heating when the CH room thermostat switches it off because there is insufficient flow to carry the residual heat away. In order to get rid of this heat, the pump needs to keep running for a while after the boiler stops (known as pump over-run) and the water has to have somewhere to go - often a requiring a by-pass circuit. So one or more of the following is likely:

• pump incorrectly wired so as not to over-run

• boiler's pump over-run control not working

• TRVs on all radiators, and no by-pass circuit

• Manual or automatic by-pass valve incorrectly adjusted

That should give you a few things to have a go at!

[Miguel]

Thanks Roger & Ed for your replies. The other thing I forgot to mention is that the boiler sometimes turns itself off and on quite rapidly. ie it goes go off/on every minute or so. Only seems to be intermittent though.

I will have a look as soon as I get a chance ie after the weekend and post back

Miguel

Roger Mills wrote:

[The Natural Philosopher]

That is consistent with very low flow through the CH circuit. As Roger described accurately

If you have an all TRV situation, try turning one up FULL - the bathroom is the favourite place.