Yes, another Baxi Bahama problem needs sorting.!!

[wp8800]

Hi All,

It would seem that unfortunatley I am cursed with one of these boilers, although to be fair, apart from the temp sensor needing cleaning a couple of times, ive not had any problems to date.

Anyway to the issue...

Started boiler on central heating around a month ago, and its been working pretty much fine until this week.

Basically the heating and/or the DHW are not working properly.

Initial problems began with the CH firing and then going off, sometimes it would restart, other times it would just cut out. ( no lock out) but it wouldnt start again after its time delay.

By manually switching it off and on again at the wall or on the boiler, it would start up again, and either keep running or cut out again.

It also has a fault of not switching on on the timer, I mean not even firing. Again, a switch off/on seemed to help.

Another time, it will run and the CH will get hot and work 'fine', but I noticed on occasion that the pressure goes up to nearly 3 bar, and im not sure exactly if it stays just under the relief pressure of if the valve is operating. (think i can hear a sort of clicking when its at this pressure so wondering if that the valve)

It seems to work 'ok' with the DHW, and seems to swicth from Ch to DHW ok.

Boiler is around 7 years old.

Ive pressed the valve in the EX vessel, air came out no water, and although I havnt messured the pressure, the air came out quite well. (comparing to a car tyre being 28ish psi, and the EXV being 14ish)

When cold, the boiler pressure doesnt drop below 1bar, (maybe a tad under sometimes)


Im a car mechanic and general good DIYer, so can hopefully get this fixed myself (unless its gas prob of course)

Ive read loads of posts about this boiler and am aiming towards the flow switches and maybe the EXV, its just that the range of faults make me want to post first for your advice.

many thanks for any suggestions

Wayne

Also - I have the original service instruction book,and while it has a good diagnostic flow chart for the DHW, the one for the CH basically just shows how it works. and due to the seeming big range of faults I have, its difficult to judge what is not working.

 

[baxpoti]

Primary flow switch needs replacing.

With the primary flow switch removed, pop a finger in to the chamber, it should be clean and smooth, use an old toothbrush to clean.

Primary flow switch should have a spring on it.

Check expansion vessel pressure with boiler drained, re-pressurize to 1 bar if necessary.

 

[wp8800]

Hi, Thanks for that,

I decided a minute ago to just clean the flow switches anyway, left my office (always cool as near outside door) and found the heating was on in the rest of the house!

I checked the boiler and found that it was running at nearly 2.5Bar (on the line between the red and green)

I switched the heating off and it took around 1 min to drop to nearly 2 bar.

Does this offer any further thoughts?

What does the flow switch(s) do exactly? (Meassure flow - i know, but for what reason)

thanks

 

[wp8800]

Also, do i need to drain the boiler to clean/replace the flow valve?

If so where is the drain plug for th boiler and how do i fill it back up

many thanks

 

[pannierstan]

You might want to get the syphon trap updated to the later one or better still pull the wire off it as I found a Baxi engineer had done on a job I visited

Stan

 

[Baxmax]

You might want to get the syphon trap updated to the later one or better still pull the wire off it as I found a Baxi engineer had done on a job I visited

Stan

 

[pannierstan]

Thats what I did !

Stan

 

[wp8800]

ok thanks.
syphon trap?

havent heard of that one before, can someone give me a hand where to find it etc?

thanks again

 

[mikej2005]

Also, do i need to drain the boiler to clean/replace the flow valve?

If so where is the drain plug for the boiler and how do i fill it back up

many thanks

Ex-Baxi Bahama owner here - you have my sympathies !

I replaced many parts on my Bahama over the years, including a flow switch, pressure relief valve, air bleed valve and the ignition board.

My problems included over-pressuring as you described and also the boiler would regularly lock you out if you didn't turn the hot tap on fully enough. (Pressing the reset switch and leaving it for a while would usually sort the latter problem out, although eventually replacing the HW flow switch seemed to alleviate the problem and make it less frequent)

To drain the boiler in order to replace the flow switch or repressurise the expansion vessel, you need to isolate the boiler with the two nuts on the send and return elboes and I think at least one of these also acted as a drain-point (the manual has some quite detailed diagrams in it).

It's probably worth mentioning that after I did this the second time, one of the elboes started leaking slowly and would have ultimately needed replacing (had I not sold the house !)

Incidently, I also never came across a 'syphon trap' on the Bahama - is it called something else ?

 

[wp8800]

Hi Mike, thanks for that info, will be trying it in a minute.

I guess the elbow started leaking as for most of its life it stays in one position, then when it gets moved all sorts start happening.

Used to happen on cars all the time, explaining it to a customer wasnt easy!!

will let you know how i get on.

thanks

 

[baxpoti]

You might want to get the syphon trap updated to the later one or better still pull the wire off it as I found a Baxi engineer had done on a job I visited

Stan

It's a Bahama not a Barcelona

On the old short traps it was common practice to remove the earth wire, stopped a lot of nuisance lockouts and if the trap did fill up it would overflow and earth on the metal base.

 

[Baxmax]

You might want to get the syphon trap updated to the later one or better still pull the wire off it as I found a Baxi engineer had done on a job I visited

Stan

Sometimes words are not required.....

 

[wp8800]

just an update, not had time to drain the boiler yet, prob going to wait until the morning now, just in case anything goes pear shaped!

will let you know.

thanks

 

[pannierstan]

You might want to get the syphon trap updated to the later one or better still pull the wire off it as I found a Baxi engineer had done on a job I visited

Stan

It's a Bahama not a Barcelona

On the old short traps it was common practice to remove the earth wire, stopped a lot of nuisance lockouts and if the trap did fill up it would overflow and earth on the metal base.

OOppps sorry

 

[wp8800]

HI All,

Ok, drained the boiler as advised, fairly easy, although i did find some water still came out when i took the flow swicthes out, so have some towel ready.

Both swicthes had some black 'crap' on them, so i cleaned them and also the pipes they sit in.

Put back together, refilled system, checked for leaks, and fired the CH up, ran and lit, kept going and is running now.

I Wanted to check the pressure on the Expansion vessel while the boiler was drained, but didnt get chance, so will see how it runs, and if i need to, i can do it later easily enough.



For anyone who might read this thread in search of a cure for their own faulty Baxi bahama, i have listed the information and useful stuff which I gained over my own search for help.

a) it seems the Baxi bahama has many common faults
b) symtoms usually include 1 or many of these:
Over pressuring
losing pressure
DHW not working
DHW working intermittantly
CH not firing
CH not heating

c) The general consensus seems to be that most of these faults 'could' be caused by the commom failure items on the baxi:
Flow switches (1 for DHW and 1 for CH)
Expansion vessel pressure wrong
Expansion vessel broken

d) other fairly common faults seem to be CH pump not working, sometimes needs cleaning.
Diverted not working properly.


I would suggest that if you find yourself reading this and your boiler has similar faults, even quite similar, I would clean the flow valves and see what happens, if you can measure the pressure of the expansion vessel while you have the boiler drained, all the better.

If it doesnt fix it, then spend the hours trauling and reading to find a cure, but at least you will know whats what with your flow switches and EXV.

It took me longer to find and read through all the posts trying to find 'the exact problem and cure' than it did to just clean the flow switches. (which took about an hour from start to finish)

Anyway, thank you to everyone who inputed on my thread and good luck to anyone who owns a BAXI!! LOL

P.s. If any heating engineer wants to change anything I have advised, please feel free. Im a car mechanic by trade, so dont claim to 'know' these things, just offering general advice on my findings.

thanks again all

Wayne

p.p.s if you need any advice on cars, let me know, ill see what i can do.

(In motor trade 16 years, owned own garage and MOT station for 9, dealing in car parts for 2. I was also an MOT tester for 5 years)