Motorised Valve Tripping house electrics

[Peter West]

Hi everyone, just to say this is my first post, I'm not a professional but have had a lot of DIY experience over the years and installed a couple of systems in my time in my houses through the years. So I'm well aware when I'm out of my depth!
My problem is that I'm on my third motorised valve (heating side). The senario is, firstly, the house electrics trip, and after isolating the heating side motorised valve (two port), from the heating circuit, the house works fine once again. When I connect it back and switch in the heating, the valve takes a few seconds to open, then when the auxillary circuit switch close in the valve, bang, the electric trip again. So the fault is in the auxillary switch circuit of the motorised valve. All well and good, I buy a new one, fit it, then probably about 9 months later, the same thing happens again. I'm on my third now. Please any ideas!!, once, I can put down to a faulty valve, but three times, no. There is something else going on. Help please. I forgot to mention, I only replaced the motor head

Peter

 

[Chuck]

I'm well aware when I'm out of my depth!

Throwing parts at a problem you don't understand is a good way to waste time and money. It's not appropriate to diagnose this sort of fault over the internet without eyes-on and the right type of test gear. Eyes-on are needed to check that there are no 'stolen neutrals', and other wiring issues and test gear is needed to check for borderline insulation faults, correct earthing, etc. Also, if it's what I think it is, the whole system should be inspected and checked.

Your best bet is to find a local independent heating engineer or an electrician who is confident with central heating wiring (not all are, ask them). It won't be difficult for someone who knows what they are doing to diagnose and fix.

 

[Peter West]

Thanks for the advice. I've already called my favourite electrician and I'll see what he says. A thing to note is that the auxillary switch is not being switched on, I've just checked with a meter. I'm running the central heating with no problems just by bypassing the switch with a direct connection at the junction box. It's a temporary fix to give us heating until the solution is found. I suspect that it may be the valve is not travelling to compete the contact with the switch, which means the mechanics of the valve itself are not running smooth, I'm about to check it out.

 

[Sharp Point]

What’s tripping, mcb or rcd?

 

[Peter West]

An update, there is no restriction of travel in the valve, it is moving fully. The auxillary circuit switch is closed properly. However I noticed that there is 17 ohms of resistance that doesn't seem right in a switch. I just want to point out if I bypass the switch the whole system runs perfectly.

 

[Peter West]

The RCD is tripping

 

[Chuck]

The RCD is tripping

Which is a definite sign that you have an insulation failure somewhere or the wiring has been done incorrectly and is in a potentially dangerous state.

When did you say your electrician was coming?

 

[Peter West]

I'm waiting for him now, I have at least Isolated the area of the problem. That's one thing

 

[Murdoch]

Valves, electricity and water ... Tripping RCD .... Any evidence of leaks?

 

[Sharp Point]

Have you been replacing the complete zone valve head or just the synchron motor?