Baxi Barcelona; condensate trap?

[alexp.1]

Baxi Barcelona with Heatrae Sadia Megaflo CL250. 17 rads.
Boiler about 5 years old. Last serviced June 2005.
CH has been on daily for last 4 weeks or so with no probs.

Woke up to rapid banging this morning (the boiler, not the wife).

Loud gurgling noise from boiler, green Mains light and red Lockout/Overheat light both flashing. Pressure gauge at 3 Bar.

Turned boiler off with the control knob, and the pressure quickly returned to it's normal 1.5 Bar level and things quietened down. Waited a few mins then turned on again, turning the knob to it's normal 10 o'clock position. Same thing happened.

I have noticed a small leak from the boiler for the last week or so (about a tablespoon of water every 24 hours). Could it be that the condensate trap is blocked and is overflowing, triggering a shutdown?

Am I allowed to empty the trap myself or will I be arrested by the Corgi police if I remove the front cover?

Also, have read about perished combustion chamber door seals. Could this cause the symptoms described?

 

[alexp.1]

Have been playing around with the boiler since I got home. Not sure what's going on now.

Actually seems as though the boiler is now firing and heating independently of the main roomstat in the hallway. ie the boiler will stay on even when the set temp level on the roomstat has been exceeded, or it won't switch on when the temp drops below the set level. Also sounds as though the fan is whirring away even though the boiler is not heating.

 

[COG]

Not familiar with your model but the sudden rise in system pressure plus overheat indicated and a banging noise all sound as if your pump has or is stuck plus the fan running on is prob on overheat (pcb trying to keep the heat ex cool)

 

[alexp.1]

Turned down the boiler control knob last night and left the boiler on via the CH/HW timer.

Started up fine this morning. No funny noises and rads nice and warm.

Odd thing was the boiler was starting up then switching off after a few minutes about 5 times between 5.30am and 7.00am. Why would it cycle on & off this quickly?

 

[alexp.1]

Slowly reading through relevant posts on this forum.

Would the violent banging noises and overheat be pump-related? Is it worth seeing if the pump speed can be increased, or would this have a negative knock-on effect down the line?

 

[SwedishViking2]

The Leak could be from the condensate trap in which case the water will short out the ignition spark to the boiler. Depending on the situation this could cause an "explosive" start if it then managed in the subsequent ignition cycles to fire as this would be with additional gas.

As for the pressure at 3 bar, do you have an adequate expansion vessel and working safety pressure valve fitted (which should open at 3 bar)?


EMPTYING THE CONDENSATE TRAP (EASY MAINTENANCE)

Switch off unit...

Please check underneath the boiler for a yellow plastic cap. Unscrew let drop into something which can catch the water with deposits that normally start to flow...

Put back the plug and start the boiler.

OVERHEAT

The unit has overheat protection and as such alternative remedy methods should be avoided. Suggest you get a BAXI engineer out to check the unit if it continues to play up. Posted advise elsewhere on this site that may help you...

BR Swedish Viking

 

[alexp.1]

Overheat/banging problem solved:

Boiler was incorrectly wired when installed 6 years ago.

When HW/CH is up to temp the boiler instantly switches off completely, instead of running-on for a bit to dissipate the heat build-up. Result is a stagnant block of water that explodes!

Surprised the symptoms haven't happened more frequently.

Humble apologies to the mighty Baxi Barcelona.