back boiler cutting out

[dave-evo]

baxi bermuda back boiler keeps going off after about 20 seconds, keeps knocking pilot off too. flares up when lit, stays lit for about 20 secs then goes out, any clues, cheers, ps had it serviced last week and stayed on for 1 day then back to normal

 

[kevplumb]

is the pump working

 

[dave-evo]

pump definately running

 

[kevplumb]

is the pump pipework hot both sides

what system is it connected to

 

[dave-evo]

was for a short while, connected to a cylinder upstairs for hot water

 

[dave-evo]

also has a header tank

 

[kevplumb]

was for a short while, connected to a cylinder upstairs for hot water

no radiators then

 

[dave-evo]

has radiators too but no heat or hot water

 

[kevplumb]

right

1 which model is it

2 man or electronic

3 gravity h/w or fully pumped

 

[dave-evo]

bermuda c3? controlled by wall mounted control panel and believe its a gravity fed system. don,t know a lot about this system as its mainly advice for a friend. do appreciate your time and help tho

 

[kevplumb]

going by your first post

it's a flow (or lack of) prob

but i can't understand why it was ok after it was serviced

 

[namsag]

Classic dirty pilot symptons . pilot strong enough to hold thermocouple but when main burner comes on it pulls pilot from the thermocouple causing it to cool and drop out.

When pilot is on is it about an inch long andstong an blue.. if its yellow and lazy or blue and small this is the problem

 

[kevplumb]

ps had it serviced last week and stayed on for 1 day then back to normal

that's what threw me

 

[namsag]

Yeah agree kev. But think he will have to get the guy back to do it properly at no extra cost unless parts

 

[dave-evo]

hi, thanks for all the advice, just got back from work and asked him to check pilot, he says its a yellowy candle like flame so done as you all suggested and told him to bring gas servicer back and pass on info gained from you all, many thanks for all your time and patience dave