back boiler has mind of its own

[karen37]

my back boiler controls both the heating and water both of these are switched of but the boiler keeps firing up as if the water or heating were on can anyone advise on this

 

[ollski]

It could be the programmer or the motorized valve....are you any good with a multimeter?....some system details would help though.

 

[karen37]

It could be the programmer or the motorized valve....are you any good with a multimeter?....some system details would help though.

I don,t have any details but i was advised to switch of power to the pump and switch it on when i need 2 heat the water until i can get someone out to it

 

[doitall]

Could be something simple like a frost stat.

 

[ollski]

Could be something simple like a frost stat.

Could be, but I can't really see why you would wire a frost stat on a back boiler.

 

[karen37]

Could be something simple like a frost stat.

Could be, but I can't really see why you would wire a frost stat on a back boiler.

it,s all quiet now that the power to it is of the council thought it might have been the thermostat in the water tank so they put a new one in but that obviously hasn,t worked

 

[B.O.B DOLE]

my back boiler controls both the heating and water both of these are switched of but the boiler keeps firing up as if the water or heating were on can anyone advise on this

if it keeps firing up with all switched off there as to be power being sent to either room stat or cyl stat from programmer so i will go for the programmer

 

[Slugbabydotcom]

A polarity check wouldnt go amiss before renewing the programmer

 

[B.O.B DOLE]

A polarity check wouldnt go amiss before renewing the programmer

if a polarity check was done this would only determine if it was reversed
but if the boiler as gone like this all of a sudden i cant see it being reversed polarity?

 

[doitall]

Could be something simple like a frost stat.

Could be, but I can't really see why you would wire a frost stat on a back boiler.

What difference does the boiler make

Frost stat is to protect the building/system not the boiler

 

[ollski]

Could be something simple like a frost stat.

Could be, but I can't really see why you would wire a frost stat on a back boiler.

What difference does the boiler make

Frost stat is to protect the building/system not the boiler

From what?..the next ice age??. I'm going for the motorized valve bob....let battle commence

 

[doitall]

From what?..the next ice age??. I'm going for the motorized valve bob....let battle commence

 

[Slugbabydotcom]

After a recent experience where someone had changed a motorised valve and made a mess of it. It took me a while to figure out why the boiler "had a mind of its own" I didn't get to the bottom of it but whilst trying to find out what was turning up live at the wiring box I got a blast from a 'neutral' wire. Howcome I always have to learn the hard way?!!!
Turned out the qualified electrician who had been there before me and swore that he had everything as it should be had wired up the fused spur the wrong way round!!!. Now I check the polarity as a matter of course. So even though the system will work with the polarity the wrong way round it's easier to trace where the live feed to the boiler is coming from when you are sure the polarity is right. Its also good working practice.
Don't know when it happened but I heard of a Vokera engineer who was kneeling on a wet stainless steel sink top whilst working on a combi which was reverse polarity. He touched a live 'neutral' wire and it killed him!!! Now all combi's are manufactured so as not to work unless the polarity is correct.