Baxi WM 512 RS - HELP

[Paul309652]

Hi
I’m new here and it’s possible this might have been covered before so please bear with me
Got a problem with my parents (30-40 year old) boiler
It fires up but after about 10 minutes, it shuts down
This happens repeatedly
They haven’t the money to replace it as most engineers that have been in previously say the whole system, pipes, rads etc needs replacing

Could this be the thermocouple?

any other advice would be appreciated

Thanks in advance

 

[CBW]

It could be a few things. Does it go to a fault?

 

[DP]

Check the pump
If it is doing that during hot water, assuming you cannot select CH by itself (hot water also switches), boiler doing that is normal

 

[ianmcd]

Could this be the thermocouple?

Definately not the thermocouple, does the heating work ? does the HW work ?

 

[ianmcd]

It could be a few things. Does it go to a fault?

The only fault codes you get with these is they either dont come on or the bang like fook

 

[DP]

The only fault codes you get with these is they either dont come on or the bang like fook

All the fault codes are verbal froM those using this boiler.
Some of these codes are listed below
It Is Working
It Is Broken
Burner Is On
Pilot Is on
Pilot Is Out

 

[Paul309652]

Hi all
Many thanks for your replies
It’s moved on slightly
Today it is not firing up at all
The pilot remains constant
The pump is running
The boiler stat seems to be working in that it clicks when turned from off to high and it appears the gas valve clicks as well. I assume this is to open the gas valve to allow gas to the jets
The room stat is calling for heat
I have checked the 3 way valve. This is operating correctly. It moves when hot water is selected and returns when de selected
The system has water in the rads
Gas is at the valve otherwise the pilot wouldn’t light
The time lock is set to constant and is new

Im at the end of where to test or look

Everything says it should fire up but it’s not

any ideas appreciated

should I order a replacement gas valve or thermostat kit?
They seem to be available

many thanks

 

[ianmcd]

Im at the end of where to test or look

Start by answering the questions

Definately not the thermocouple, does the heating work ? does the HW work ?

not asking the question for fun

 

[Paul309652]

Are you trying to be funny ianmcd
What part of “it’s not firing up” didn’t you understand
If you think I’m on here for fun and to feed your ego, I have better things to do with my time

my detail above answers all the questions
If it doesn’t fire up, the heating doesn’t work and the HW doesn’t work

if you want to provide helpful advice, I would be grateful
If you just want to criticise, don’t bother

 

[Gasguru]

If you are sure the gas valve is operating for the main burner when you adjust the thermostat then you need to call a gas eng. strictly non diy.
No point in buying anything until the rest of the boiler has been checked out, may not be a viable repair if other probs are found.
Not many of these models left....

 

[Paul309652]

Thank you gasguru
That might be the best alternative
I did manage to get it to fire up
I turned everything off, including the pilot for around an hour so that it was all cold
Went through the startup procedure and It fired up
However it’s back to the previous issue where it shuts down after 10-15 mins
It is re starting once I turn the pilot off, re ignite the pilot and turn the room stat up.
I am getting heating and HW when it’s running

The pump is definitely running correctly on speed 3. It has options for 1,2&3 speeds and I have tried on all 3
Just need to resolve or understand the issue of it shutting down (room stat is set at 30deg so that it constantly calls for heat)
that’s about all the info I can provide and I am thankful for your help/advice

 

[CBW]

The pump is definitely running correctly on speed 3. It has options for 1,2&3 speeds and I have tried on all 3
Just need to resolve or understand the issue of it shutting down (room stat is set at 30deg so that it constantly calls for heat)
that’s about all the info I can provide and I am thankful for your help/advice

It could be a weak pump, failed pump etc, it might be running, but not dissipating the heat correctly, or it could be down to your gas valve failing. Try, being careful feel what the pump temperature is like, if too hot to touch or raging hot, then it could be pointing you in the right direction.

FYI @ianmcd provides sound (bearing in mind Free) advice, as does @Gasguru and many other respected engineers/contributors.

 

[ianmcd]

Dont know why I giving you free advice but most likely that you have a blocked cold feed, merry christmas get the blankies out

 

[Hugh Jaleak]

The fact it is firing and then shutting down, suggests there isn't actually any fault with the boiler itself, the symptoms are pointing towards the heated water not getting away from the boiler and around the system, hence boiler is up to temp and shuts down. That's why you've been asked what is working? Need to check the pipework and see how far away the heat is getting from the boiler.

Wouldn't be the first time we've come across a pump that appears to be working but in fact, isn't actually circulating any water....

 

[Paul309652]

Thank you The Novice
Yes it does feel very hot when the boiler is lighting the gas during the 10-15 minute periods
This could be a starting point for me as pumps are not too expensive and fairly easy to fit
I would assume very easy to trained Heating Engineers

I will give it a go

thanks again