Baxi Solo 2 Boiler Problem

[Theblade]

Hi You all out there, Hopefully some kind person can advise me on a slight problem I have with my "BAXI".

From time to time there is a rumbling from the boiler which I suspect is due to the pump not running on for its 8-10 minutes cooling period......Have tried to find out manufacturers instructions for overrun boilers but no luck!

I have just about made a complete overhaul of the whole system...New heat exchanger, New PCB, New programmer, New diverter valve, New cylinder thermostat, New room thermostat where do I go next?

I am told that the boiler thermostat controls the overrun so have just ordered that.....As you can see I do need help befored I give in to the professionals

Regards, Theblade

PS...it is qiuite possible that this problem has been hi-lighted on an earlier forum so will take a look see...

 

[Sharpend]

It would probably have been cheaper to just replace the boiler with a new one, but seeing as you haven't and the problem still exists, the first question is had anything been changed or altered at the time this noise started?

 

[NozSpark]

Surely it would have been cheaper to have got someone in to have a look at rather that replace a load of random parts in the hope that it'll fix the "fault"

Pump over run is to help reduce the chance of damage to aluminium heat exchangers from retained heat.... it was never a problem with the old cast iron ones

How old is the boiler?

How long does the rumbling last?

Does the rumbling coincide with the flame lighting?

 

[Theblade]

Theblade again........I thought while I was working on the system that I would overhaul it....The cast iron unit was brand new and donated by my next door neighbour so no cost involved. The pump was quite old so while system drained down I replaced it along with the diverter valve. The valve was changed as I didn,t seem to be getting heat into the radiators.....

Ah well here I am , the wife is angry and I have a headache from it all

The rumble comes on when heating satisfied and only for a short period....Yes you are absolutely right I should have called a profesional in but I didn't so am trying to get a fix......I feel sure it is a wiring problem and am trying to sort that out at present....Have asked the Baxi people what controls the overrun, I think it is tied up with the PCB and boiler thermostat.

Anyway many thaks for looking at my cry for help and as it is the week end I will have to wait until Monday to get an expert in.....I might have got over my headache by then!

Regards, Theblade

 

[Theblade]

Having read thru a lot of the topics it looks like I need a good "sparky"... can you recomend one locally....TN6 2HN....?...Thankyou

 

[steptoe]

if this has only just started then I doubt its the wiring,

unless of course it has been changed around by someone.

the wiring cant have changed on its own, so it must be a part failure of some sort.

 

[Theblade]

I am guilty.......I thought I had everything identified when I replaced the 3 way diverter valve!! When I reconnected everything I ended up with a loose wire!! I traced this back to the back plate of the programmer located downstairs.....`When programmer powered up this "wire" is live - 240V but I can't identify where it should be connected on the junction block hence your advice to get a sparky The Baxi 2 has an overrun feature and I have just received a replacement boiler thermstat

 

[SLIPSHOD & SLAPDASH]

 

[ProDave]

....

The rumble comes on when heating satisfied and only for a short period.... 

That sounds to me like a motorised valve has closed as there is no call for heat, and the over run pump is trying to pump into a dead end.

If so it's a system design fault, not a something broken fault.

Try adding an automatic bypass valve, which is a job for a plumber.

 

[Theblade]

How do I download 012ham.jpg posted by distinguished member....message says I do not have permission!

 

[a3]

How do I download 012ham.jpg posted by distinguished member....message says I do not have permission!

I replied to your support ticket explaining why

Try Now

 

[Theblade]

Staff....Many thanks I did get your email and just went to try and download but the item seems to have been removed from the forum!

The situation  at present is as follows.....I popped into a neighbours house to take a look at his wiring set up....same house, same builder....took a picture and am working it all out to see where I am going wrong on the Drayton wiring diagram which would seem to be for a boiler with no overrun.It shows the boiler connection tied in with the diverter valve "orange" whereas the neighbours wiring has the pump tied in with the "L" pump connection at the boiler. Can Steptoe confirm this please?

 

[ProDave]

The Orange is the switch wire from the valve and is the "call for heat"

In a conventional boiler, that will feed L to the boiler and L to the pump.

In the case of a boiler with over run, it will feed L only to the boiler.  The boiler will also have a permanent L connection and will switch the pump from it's own circuits to ensure the pump continues to run for a certain time after the burner has stopped firing.

So in your case, the pump should be connected to a dedicated terminal in the boiler for this purpose.

It is of course quite possible yours has been wired wrong right from the start. A lot of electricians (and plumbers) have trouble getting heating systems wired properly.

 

[Theblade]

Prodave....Thankyou....what you have said ties in with the neighbours central heating wiring ...His pump is separate from the orange and obviously goes back to the boiler wiring.. So is it possible if the boiler thermostat goes on the blink it could cause the pump to run continuously?

Hopefully the drayton junction housing will arrive tomorrow and I will double check the wiriing....I had hoped to get it today but one can't rely on the Royal Mail....

The dedicated terminal on the boiler is "L" and I will check to see if in actual fact it is the same at the "junction block"....Thanks again...

 

[SLIPSHOD & SLAPDASH]

I believe none of the controls (programmer, stats, valves etc)  wiring diagrams have been updated for over 20 years and don't show the permanent live to the boiler nor  that  the pump is now connected to the boiler for the run on  supply & not paralleled up with the boiler switch line.

 

[Theblade]

Theblade again with an update to the problem of my Baxi 2 boiler system. Thanks to all those nice people out there with comments etc on this system and help in an effort to sort out this problem.

The wiring diagrams that I was working to did not show the connection with the pump overrun system so there was little chance I could get the job done correctly.....obviously slipshod knows all about this as does Prodave who guided me to the solution!

When I removed the backplate from the programmer I located the boiler/pump wire but couldn't believe that an electrician would make an electrical connection just by twisting wires together and wrapping with black insulating tape!! Obviously this was done when the original system was installed many years ago...To cut a long story short I made the correct connection and checked all wiring from programmer end to main junction box...all satisfactory and heating now back to normal.

Thanks again to all for help and comments it was much appreciated and kept me going with the ultimate aim of solving the problem....I now have an overhauled system ready for the winter...CHEERS....Theblade

 

[Sharpend]

Having read thru a lot of the topics it looks like I need a good "sparky"... can you recomend one locally....TN6 2HN....?...Thankyou

No what you needed was a ruddy good forum!!!!

Good job you found it!

 

[SLIPSHOD & SLAPDASH]

Thanks for the update, So are you saying it was only a free fix of a  bad twisted connection at the controller  ?

 

[Theblade]

Goodmoaning all...Theblade here....An update on the saga of my "re-conditioned " Baxi 2 boiler system....Since I rectified the 2 loose wires behind the programmer wall plate and replaced the boiler thermostat the system has been behaving itself. I didn't give up on the problem as I had the backing of the forum who, themselves, were interested......It would seem that my main problem was the pump connection which was shown on the diagram as hooked up to the "orange" diverter wire.....WRONG....it needs overrun hence the wire behind the back plate from the boiler pump connection..."L".

Would it have been cheaper to install a new boiler? The answer is a definite NO....To have called an electrician in would have been expensive and a loss of face....

So there you have it, thanks again to you all....I shall keep looking, you never know I might be able to help someone in trouble out there....

Regards, Theblade