boiler problem

[hendo127]

hi there i have a brittany 80 comi boiler the problem is when it flashes up for the radiators it only stays on for litulary a minute and will continue to do this off and on.

when hot water is required this is fine and it reaches the 85 degrees no problem

any ideas guys?

 

[Rob]

is anyheat gettin to the radiators at all after the boilers been on for litulary a minute

 

[hendo127]

yer they begin to get warm before it goes off

 

[Rob]

look inside boiler to the left hand side you'll see 2 purple leads on a thermistor take these off and connect to the the thermistor with the green leads just to the right.

what happens?

 

[hendo127]

what should i be looking for?

 

[Agile]

Just do it and tell us what happens!

 

[hendo127]

when it fires up it constantly stays on and even if i turn the dial control it makes no difference

 

[Rob]

thats good. so everything gets hot? it could be two things

1) you need to replace the thermistor with the original purple leads. or if your tight you can just swap them over. HW one has little function.

2) unlikey, but a partial blockage etc etc.

 

[hendo127]

thanks for the quick replys rob just a quick couble of things

1. i though of changing them myself but how does it come off ive took the pin out and thats where i got struck.

2. Where would i get a new 1 from?

cheers for the help

 

[Rob]

after the removing the pin it just pulls out, sealed with O rings...but drain boiler first .....

the one on the left is the heating one, so the primary side needs drainin. dont worry about changing the one on the right.

to drain the system you need to attach hose to radiator drain valve which should be at lowest point on system. and re-fill via the filling loop.

you can buy one at any hrpc or boiler spare specialist.

1000733 is the chaffateaux part number

 

[hendo127]

rob thanks for the advice could you expain how to drain the sytem again also why does it need to be darianed ?

cheers

hendo

 

[Rob]

the thermistor what your changing sits in the water. basically you need to drain the water which is in the radiator circuit.

look on the pipe work next to your radiators. usually the one nearest front or back door will have a valve attached which you connect a hose to run outside then open the valve this will empty the boiler.

if you dont feel confident then may pay to get a heating engineer round. tell him you think you know what the problem is. and maybe get the part prior to his visit.

 

[hendo127]

this may sound daft but if the boiler is off thus the pump isnt running could i not just pull it out that way and then put the otherone straight in???? are am i just talking balls lol

cheers for all the advice by the way

 

[Rob]

lol....NO! you, your kitchen and more importantly the circuit board/electrics will get soaked!

 

[hendo127]

roger that! i will try to drain it myself if not get someone in. is it acting as a bung at the moment for the water and it just prise out once drained?