I have the following problem. When the hw system is switched on (either manually or at programmed times), the mcb trips. However if switched on when I have the cylinder stat down on it's lowest setting, and then I turn the stat up, the hw system doesn't trip and the boiler lights up. What does this indicate ? I have already replaced the programmer and cylinder stat, so it can't be a fault with them...or deos this belong to the plumber forum ?
Aye....check synchronous motor on 3 port motorized valve if it is presumably Y Plan..if S Plan check both motorized valves. Could be knackered field windings causing the problem....I stress could be.
I'm no expert but i would first of all try changing my breaker type from most likely a type b to a less sensitive type c
thks but i'm not sure i want to change the breaker type as the whole system has been working fine for many years before this problem occur.
I'm no expert but i would first of all try changing my breaker type from most likely a type b to a less sensitive type c Goodness me......
i have tried isolating everything and still come up with no conclusions as the damn rcd seems to trip out randomly now. Somethimes when it trips, I reset and turn the boilder back on and it works fine. I think surely it must be a wiring problem. Am i right to assume I should get an electrican in rather than a heating engineer?
Have you taken the motorized valve cover off and had a look?......could be a problem inside....possibly a very slight amount of water leaking past the spindle gland etc wetting the microswitch contacts/synchronous motor going down etc.....whatever you do....do not fit a Type C MCB.
JP, I have taken the plastic cover off and nothing looks at all wet or damaged, and the cb looks to be undamaged. It is definately a RCB tripping.
Its not a wind-up, I really am that clueless. Do you think I need an electrican or a heating engineer for this ? thanks.