Strange boiler behaviour

[joeh]

Hi guys, I'm hoping for some insight.

We've got a gas boiler feeding our hot water tank and radiators. Recently serviced and everything was fine. The pump, diverter valve, and other bits are in the ceiling above our kitchen. Long story short, we replaced the kitchen light a few days ago (the old one broke while trying to remove a jammed bulb). We got an electrician out as we needed an earth for the new light, but couldn't find one (it'd been poked way up into the space above). So we put the new light in, working fine, and went to bed.

We got up in the morning to find our hot water was cold, and strangely, all our radiators were bloody hot (despite the room stat being off). So, fiddling with our programmer (we normally leave water and heating on and just change the room stat if we want our heating off for the summer), we found the following behaviour:

Hot water off, heating off - boiler does nothing, radiators cool down, no hot water. What you'd expect.

Hot water on, heating off - boiler comes on straight away and runs continuously, hot water stays cold, but the rads get bloody hot again.

Hot water off, heating on - boiler comes on straight away and runs continuously (despite the room stat not asking for heat), hot water stays cold, but the rads get very hot. Why's it doing that?

We got in touch with the electrician, who thinks it's the diverter valve, and he's planning to replace it (seems very coincidental that it's suddenly stuck - and stuck on heating rather than hot water, which is all we've been using for a few months). In the mean time, he's set our existing one to send heat to the hot water only. But the boiler seems to be running a lot more often now though, and our water is hotter too.

So what I'm really asking is is there any way things could be miswired that might cause this kind of behaviour? Right now we're just planning on waiting for him to replace the valve and see if it is that that's gone.

Thanks,

Joe

 

[WHPES]

You need to check the diverter valve before replacing it (see if the signal is getting to the valve). Can you move the manual lever OK?

 

[wnjswozo]

get your electrics inspected "no earth" doesnt sound good

 

[Billy Bob Bob]

my theory is this ,there was no earth in the light,the spark has run a earth from the heating(or what he thought was one) the earth in the heating has been used as a control wire by the berk that fitted it

 

[stevetheplumber]

agree with gasman often find earth wire used on room stat in particular
id remove the earth wire the sparks fitted and see if the problem disapears
but turn the mains of as the eartrh could actually be live

 

[oldplumber]

wots a sparky doing replacing motorised valves? Id want him o check the elecrics first as per gasmans coments

 

[joeh]

Thanks guys!

Disconnecting the 'earth' has sorted things out. I'll get someone else in to check the wiring!

Joe