help with a main combi 30he

[cdodds2004]

Went a main combi 30he that was locked out on flame failure. When I reset it it lights but doesn't rectify so them drops the flame.

So I messed about with the leads etc and when I disconnected the the rectification lead from the top of the condense trap it then fired up and rectifies? Anyone else had this problem with the condense trap or what causes it to do it? The trap was empty pretty much.

Any help would be appreciated

 

[Billy Bob Bob]

screw too long in top of bottle and has corroded,was a few like this,try a shorter screw

 

[Leo21]

Or fit a new trap, they're cheap. Quite a common fault.

 

[cdodds2004]

Corroded and what does that do? Causes a no signal back to boiler or sends a signal when it shouldn't be there? Must be rotten inside as it seemed OK at the top?

 

[cdodds2004]

I have had the intermittent fault like this on solos a few times but never on a combi? What is the corrosion actually doing?

 

[Billy Bob Bob]

Corroded and what does that do? Causes a no signal back to boiler or sends a signal when it shouldn't be there? Must be rotten inside as it seemed OK at the top?

sticks through to far and rots,as leo said,traps are cheap

 

[cdodds2004]

What's the screw actually do? When it's wet it cuts out due to blocked condensate

 

[Billy Bob Bob]

What's the screw actually do? When it's wet it cuts out due to blocked condensate

yes,it causes the pcb to see a break in continuity by earthing it out

 

[cdodds2004]

So how does a corroded screw cause a break in continuity? Sorry for all the questions but I like to understand why the fault occurs not just how to fix it if you get me

 

[AlexGas]

So how does a corroded screw cause a break in continuity? Sorry for all the questions but I like to understand why the fault occurs not just how to fix it if you get me

When the trap gets blocked, the condensate level will rise to the top of the trap and this will create a continuity between the two contacts. And the boiler will go into a lock out. Also, check there’s no water getting onto the contacts from the above.

Rusted screws - means there’s already some liquid or moisture around. Also, it possible that there’s enough rust - small metallic particles lying around and creating the same continuity. The cradle, with the two contacts in it, needs to be clean and dry.

 

[cdodds2004]

So if it was disconnected your basically shopping the shut off for a blocked condensate. I understand that when the water rises it creates continuity and turns it off. But there was no water in the trap, so how does the fault appear when the trap is knackered ie the screw etc? Am I missing something really simple?

 

[Billy Bob Bob]

So if it was disconnected your basically shopping the shut off for a blocked condensate. I understand that when the water rises it creates continuity and turns it off. But there was no water in the trap, so how does the fault appear when the trap is knackered ie the screw etc? Am I missing something really simple?

screws probably rusted in side it,last one i seen was a very small rust stain inside of bottle,by no water,is the other side of the bottle full?

 

[AlexGas]

But there was no water in the trap, so how does the fault appear when the trap is knackered ie the screw etc? Am I missing something really simple?

You could take the wires off the two contacts and check for the continuity between the two contacts. I bet there will be one, cos that’s what you are getting in the first place. How it happens? You need to get close to the trap and get your head around it.

Have a read here too:

http://www.lovekin.net/baxi-100-HE-boiler-faults.html

 

[cdodds2004]

You could take the wires off the two contacts and check for the continuity between the two contacts. I bet there will be one, cos that’s what you are getting in the first place. How it happens? You need to get close to the trap and get your head around it.

Have a read here too:

Baxi 100 HE Boiler Faults, Problems and Fault-finding; Baxi Barcelona Too

Ahh thats a great way of testing it. Remove both wires and check for continuity. Genius

I. Love this forum

 

[cdodds2004]

screws probably rusted in side it,last one i seen was a very small rust stain inside of bottle,by no water,is the other side of the bottle full?

Was about half full at most, so could of emptied and locked out due to water getting on the long corroded long screw?

 

[Billy Bob Bob]

Was about half full at most, so could of emptied and locked out due to water getting on the long corroded long screw?

very likely

 

[buckley plumb]

You could take the wires off the two contacts and check for the continuity between the two contacts. I bet there will be one, cos that’s what you are getting in the first place. How it happens? You need to get close to the trap and get your head around it.

Have a read here too:

Baxi 100 HE Boiler Faults, Problems and Fault-finding; Baxi Barcelona Too

Wow where did you get that link from

 

[Leo21]

Wow where did you get that link from

I got o f ukpf.












































Just now.

 

[cdodds2004]

Thanks guys