No hot water when heating is on

[Terrywookfit]

Could be Relay T 31 & T 32 not separating. It would explain why valve only closes when heating stat is satisfied.

 

[GaZaai]

Could be Relay T 31 & T 32 not separating. It would explain why valve only closes when heating stat is satisfied.

Yeah makes sense then, I'll give you an update once the new relay has been fitted.

 

[GaZaai]

Could be Relay T 31 & T 32 not separating. It would explain why valve only closes when heating stat is satisfied.

Ok I replaced the relay. Everything seemed good it started up I put the thermostat up and the boiler was running. Next I went to go try the hot water tap to see if it would automatically switch for the first time ever and BANG a huge sound from the boiler. I go through turn it off no physical sign of anything burnt etc. But now my flow switch is no longer giving out mains to Terminal 2 when the water is on. So currently I don’t have any hot water now.

I take it the wiring could be wrong and caused the flow switch to go boom? Not sure if the new relay is damaged now or not.

 

[Terrywookfit]

Are you sure you got correct relay with 240volt coil....Finder 3PCO 6013 8230 0040 cost less than a tenner.

The flow switch only operates the relay coil so nothing to short out ........Wrong voltage coil would go Bang though.. Coil should be about 7.25 kΩ resistance
What size fuse is fitted in isolator. ?

 

[GaZaai]

Are you sure you got correct relay with 240volt coil....Finder 3PCO 6013 8230 0040 cost less than a tenner.

The flow switch only operates the relay coil so nothing to short out ........Wrong voltage coil would go Bang though.. Coil should be about 7.25 kΩ resistance
What size fuse is fitted in isolator. ?

Omg lol I put a 6V AC one in. They look identical though apart from the now obvious writing on the side of the coil. Old one says 230V new says 6V. Where is the isolator fuse and I will check for you, the only fuse I know about is the one in the plug.

I take it I damaged the flow switch with the wrong relay though as it doesn't put out 230v to terminal 2 anymore?

Thanks for your help

 

[Terrywookfit]

Fuse will be in the plug should be 5a
I would imagine you have fooked the flow switch when the coil fried.

 

[GaZaai]

Fuse will be in the plug should be 5a
I would imagine you have fooked the flow switch when the coil fried.

Ok ill give that fuse a double check and make sure its a 5A as it didn't blow.
I've already got another flow switch on the way as it was leaking really bad anyway.
I also ordered the correct Relay by using your part number above so hopefully all will work out correctly this time.
Thanks again

 

[GaZaai]

Fuse will be in the plug should be 5a
I would imagine you have fooked the flow switch when the coil fried.

Ok new relay and flow switch is in. Everything is ok and no leaks.
Original issue is still present the 3 way valve doesn’t operate to hot water when the radiators are on. If I turn the thermostat down to 10 degreees I instantly hear the valve move and hot water works. The flow switch is working fine as when I turn the hot tap on I can hear the boiler fire up and hot water comes through.

 

[Terrywookfit]

Time to trace the wiring.
Do you have a wiring diagram to follow.
First checks.

M/v Brown wire to T3. T3 to pin 31 on relay ( Common).

L from c/h stat to T on terminal strip. T to relay T 32 (n/c)

 

[GaZaai]

Time to trace the wiring.
Do you have a wiring diagram to follow.
First checks.

M/v Brown wire to T3. T3 to pin 31 on relay ( Common).

L from c/h stat to T on terminal strip. T to relay T 32 (n/c)

Yes I have a wiring diagram. The above wiring you have mentioned is correct.

Although what I have noticed is that it states “Note: When fitting a room thermostat, remove link wire ‘A’ and wire the thermostat into terminals ‘T’ and ‘H’” but there is nothing wired into H only T to which goes to pin 32 on relay?? Could this be it?

Room thermostat comes into Terminal 3 and Terminal N

 

[GaZaai]

Correction... Room Thermostat wiring is as follows:

Blue: N
Earth: Earth
Red: 3
Yellow: H

 

[Terrywookfit]

If Room stat is across 3 and H then it is bypassing the relay. which explains every thing.

 

[GaZaai]

If Room stat is across 3 and H then it is bypassing the relay. which explains every thing.

I've moved the Red from 3 to T. Will it be OK to try and turn on do you think?

 

[Terrywookfit]

Yes

 

[GaZaai]

Yes

It worked perfectly. Thanks for the help!

This must be the first time its worked since it was installed 15 years ago lol