Glow Worm Compact 80E switches on without the tap !?

[Austin10]

This morning I heard clicking and went to the boiler and noticed the domestic water heater switches on and off - without anyone using the hot (or cold) water tap !?

I switched the unit on and off and opened the tap a bit and even turned on the radiator. But now as soon as the boiler is turned on it starts heating domestic water and won't stop (water actually gets hot and it's usable via the tap).

I got worried that if water is not used and if it just keep heating it inside, it would get damaged or blow up !?!? Is there a danger of that... !?

Two years ago the Hot Water Micro Switch (with Diaphragm) started leaking which I bought a new one and changed it myself and there was no problem ever since until today. Is there a problem with that switch again ? (I recall if that switch has problem the boiler doesn't come on with the tap, now it's other way around !?)

Any suggestions appreciated....

 

[petit_pablo]

sounds like the microswitch yes.

 

[Austin10]

I was thinking the same (it's a cheap switch/diaphragm module and can be changed really easily - by myself).

But I just spoke to the guy who I bought the switch from last time and he was thinking it might be the electronic PCB board (I recall 5/6 years ago British Gas engineer replaced that too - I think it's another thing that breaks regularly on these).

It looks like £210 British Gas "one off repair service" written all over this little mishap... !

 

[mickyg]

probably the microswitch. check that first. Take it off and see if it might be leaking from the gland behind it. very easy fix. diy able.

 

[Austin10]

Just for information, I fixed this issue and it was the microswitch.

First off the problem got worse, so turning the boiler on, the domestic hot water was switching on right away and constantly (the switch must have permanently stuck). Though there is no danger as flames turn off after a while as thermostat cut it off (although the pump keeps circulating the water). So I used it for a few days by manually turning the boiler on/off as hot water was required.

Took the switch off and checked the diaphragm behind it worked by opening/closing tap.

I remembered that previously (2 years ago), the diaphragm behind that switch leaked and I had changed it, but they also sent a switch which I didn't use then. Though the switch is slightly different, and missed the right connector.

The people who sell spare parts don't help at all !!!? The Glow Worm has 60p/min help line that never answers !!? So I made up some connector from my own resources and hooked up the new microswitch and all works OK now.

I think Glow Worm has changed the switch to a new model, but for some reason does not supply the connector/cable for it. This is a problem as the old switch had cables coming out of it while this one needs a separate one.

If anyone needs more info, let me know ( I have photos of both them).....

 

[Agile]

The people who sell spare parts don't help at all !!!?

The Glow Worm has 60p/min help line that never answers !!? So I made up some connector from my own resources and hooked up the new microswitch and all works OK now.

I think Glow Worm has changed the switch to a new model, but for some reason does not supply the connector/cable for it. This is a problem as the old switch had cables coming out of it while this one needs a separate one.

Welcome to the problems that boiler engineers face every day!

The difference is that we have to solve them quickly and efficiently without inconveniencing to house owner.

Tony

 

[knellerhall]

My 80e has the same symptoms so I have ordered a new switch, diaphragm & cover. Can someone confirm if I need to drain the boiler? I have already shut off the 3 taps (and isolated the electric supply). I'm sure I have read somewhere that all you need to do is close the taps and open the hot water taps in the house to empty the dhw side of the boiler but when I do that nothing comes out. I guess there's not much water in it anyway?

Once done do I just open the boiler taps and off I go?

Thanks in advance

 

[Agile]

As long as its only the DHW diaphragm you are changing then yes.

Tony