baxi 80 eco

[amyraz]

Hi i have a baxi 80 eco the problem i am having is when you turn the heating on or run a hot tap the boiler fires up for about 10-20 sec approx
then turns of .so the water runs hot for about 20 secs the goes cold and the radiators feel luke warm on the odd occation it will fire up and run fine but this does not happen very often i have replaced the fan and flame sensing electrode i have a spare pcb but havnt tried that yet any ideas would be great cheers dave

 

[Agile]

It seems that you are a parts changer then?

Changing parts in the gas train like the fan and flame sensing electrodes should be done by a CORGI registered person unless its where you live and you are proven as competent.

Are you CORGI registered? If not then I am reluctant to give you advice as you have already changed parts which were not apparently faulty and that does not demonstrate competence.

I suppose you could change the PCB next. You dont really need to be CORGI registered to do that. Be aware that they are delicate and can be damaged by static if carelessly handled. You should use an earthed antistatic wristband!

Tony

 

[geoff@cetltd]

It seems that you are a parts changer then?

Like most CORGIs ?

Changing parts in the gas train like the fan and flame sensing electrodes should be done by a CORGI registered person unless its where you live and you are proven as competent.

... have a clue

Are you CORGI registered? If not then I am reluctant to give you advise as you have already changed parts which were not apparently faulty and that does not demonstrate competence.

The problem is that he doesn't know exactly wha the problem is ... which is why he came here asking for advice

 

[amyraz]

changed the fan as the bearings were worn and it was noisy this was done
several months ago am quite compedent am mechanical engineer

 

[ChrisR]

Careful about claiming competence or you'll get all the wagging fingers out. As in any field, there are things you won't know about, and there's always something you could get wrong.

On HW, does the boiler stay out or does it fire up again if you leave it for a while - minute or two perhaps?

 

[amyraz]

yes chris will ignite run for approx 20-30 secs then shut down again

 

[ChrisR]

SO it fires for 10 - 20 -30 secs then off for similar then repeats ?
Did it start doing this gradually?
How about the CH same or a bit different??

SOunding like sludge in secondary heat exchanger, so far.

 

[amyraz]

Yes mate noticed it over about 2 week time span central heating is the same

 

[Agile]

I have never heard of a fan needing to be changed on that model before. Is the boiler in normal domestic use or is it a hostel where its running almost all the time?

It certainly sounds as if the problem is a sludged up secondary heat exchanger if the problem is only on DHW.

It can be replaced or cleaned but unless the system is properly cleared as well, as should have been done when the boiler was installed, its likely to happen again in the future.

Tony

 

[amyraz]

tony
top bearing is fossi bronze and had worn oval causing fan to stick boiler is domestic and was installed about 3.5 yrs ago how would i go about cleaning the secondry heat exchanger ? cheers Dave

 

[Agile]

Fossi? Phosphor?

Most fan bearings are sealed ball races now and I am surprised that more dont fail on that model if they are only PB.

My first reaction as a CORGI would be to check the gas settings as over gassing causes fans to overheat and fail the bearings prematurely.

The HE can be cleaned by first filling with water and skaking out the dirt many times until no more comes out. It would probably work at that point but to do the job properly you need to use an acid. Citric acid in saturated solution warmed to 60° is good and cold 5% HCl is even better.

To use chemicals you need to be competent and use appropriate protection.

Tony

 

[amyraz]

Tony
thanks for advice cleaned out heat exchanger and all is working fine will get sysyem chemically flushed and gas settings checked bysomeone who is corgi registered thanks again for taking the time to reply best wishes to you and yours Dave