baxi bermuda 551 - firing but not staying lit

[bludclot]

any help with this is most gratefully received.

our baxi bermuda 551 has been fine until recently when the hot water temperature dropped to just about luke warm. (gravity fed system) i figured that this would be a thermostat issue and ordered and fitted a replacement. this however, made no difference.

so i followed the servicing instructions here: baxi bermuda 551 very carefully and put it all back together but to no avail - although the pilot light is stronger now and a nice shade of blue the boiler, when asked by the (switchmaster 400) timer fires up straight away but then immediately shuts down again.

any ideas as to what might be the problem please? it seems like a very simple device, the only other component to change appears to be the gas valve, but seeing as we are a low income family (but proudly not taking from the state) this would be a significant outlay.

so also would be calling out a gas man - an expense which we really cannot afford. if i can fix this myself it would be a real bonus.

 

[namsag]

What do you mean shuts down?? do you mean pilot goes out

 

[bludclot]

pilot light stays lit, main burner shuts down.

sorry, wasn't clear enough!

 

[namsag]

Does it stay on if you demand heating??
No hot water on a gravity system proceeded by it being luke warm for a while before hand usually indicates the header tank in loft has run dry and ball valve has not dropped to replenish it. Check this

 

[bludclot]

same results when heating requested via timer.

just been to loft, hot water header tank full and ball valve operating correctly. i checked the radiator header tank too while there, all good as well.

 

[matt1e]

pilot light stays lit, main burner shuts down.

sorry, wasn't clear enough!

Its may be cutting out via the stat due to poor circulation
is the pump ok?
are you sure you have gravity hotwater?
how old is the system it may be blocking up

 

[matt1e]

i checked the radiator header tank too while there, all good as well.

define "all good as well"

 

[bludclot]

yes, very sure that it's a gravity hot water system. there is no 3-way valve and the central heating pump was replaced by me in november last year, so pretty sure that's fine too.

it's puzzling (to me anyways) that the hot water just suddenly stopped from one day to the next, i'd have expected a gradual decline if a blockage was building up....?

 

[bludclot]

'all good as well' :- water in tank to about 2/3 full. valve allows water in when pushed down and shuts off when water at upper limit. no overflow leaking.

 

[namsag]

Drain off some water and see if the level falls.


You may have a couple of faults

 

[bludclot]

yes, the water level falls in the header tank when the hot tap to the bath is opened.

 

[45yearsagasman]

This could take a while.

 

[Phill Peck]

The fact you've got your head in the wrong tank worries me that your working on an open flued gas appliance with clearly no idea what your doing

No offence but ring an engineer mate

 

[Agile]

so i followed the servicing instructions here: baxi bermuda 551 very carefully and put it all back together but to no avail - although the pilot light is stronger now and a nice shade of blue the boiler, when asked by the (switchmaster 400) timer fires up straight away but then immediately shuts down again.

OK then Bloodclot, ( I hate that rude name that you chose and dont think the site owner should allow it, but he does! ).

You will know that you should not really be taking that kind of boiler apart because you dont have the knowledge or test equipment to be able to check that its operating safely afterwards and thus you put your family and neighbours at risk.

The only good advice is to get a gas reg engineer to check that its still safe.

 

[bludclot]

i hear you agile. i would love to be in a position to call out help, unfortunately due to a very work short winter i am only just covering the mortgage and feeding us, my rather large overdraft is what's keeping us going. the question for me is - do i not pay the mortgage or go hungry for some time to get the boiler fixed or do it myself?

this particular week i had a job for monday and another booked in for tuesday to friday which the customer phoned and cancelled last friday evening - so yet another difficult week.

see my motivation?

i am well aware which tank is which in my loft - the small high one is the radiator tank and the larger one the hot water tank. both are filled to the correct level and both re-fill when water is drawn off. if you think it might help i could drain the radiator system and flush each rad valve through with clean water and re-assemble...?

my work partner's father was a gas man - we are able (and have) performed a drop test once i had re-assembled the boiler. i may not be qualified but i am aware of the implications of my actions.