firebird enviromax combi lock out

[dave176]

Hi. I have a firebird enviromax combi boiler. each time it turns off the motor on the riello burner keeps running for a while then the whole thing goes into lock out. flashing green and red.
shouldn't the motor turn off straight away? I'm also getting pressure building up while it's running but the expansion vessel had gone so a plumber fitted a new one away from the boiler but put it on the return side of the flow instead of on the actual flow side, I think that's why I'm getting high pressure but as for the motor still running after it's switched off and it's no longer giving a flame then going into lock out if anyone has any ideas I would really appreciate it

 

[SimonG]

Yep, get your engineer back.

Recently serviced?

Photocell partially sooted? Which could mean flue or combustion issues.

Expansion vessel is best on return, less affected by high temperatures.

Why didnt they just fit a new one on the boiler, check its pressure and clean out connecting flexi.

 

[dave176]

Yep, get your engineer back.

Recently serviced?

Photocell partially sooted? Which could mean flue or combustion issues.

Expansion vessel is best on return, less affected by high temperatures.

Why didnt they just fit a new one on the boiler, check its pressure and clean out connecting flexi.

yea recently serviced but it was giving this problem before the service. new pressure vessel is about 10ft away from the boiler connected with 3/4 copper he left the old one connected to the boiler. the photo cell is clean too. I don't understand why the motor/ fan still runs after I've switched the boiler off at the timer control. runs for about 10 seconds or so then the lock out light next to timer controls comes on and restart button on the burner control box flashing red and green. I think the control box on the burner is different to the usual control boxes I've seen in the past. this one is a MO/535 I think?

 

[John.g]

Some low emission oil fired boilers now do a post purge after the burner shuts down, as well as the mandatory pre purge of 10 secs or so, this post purge obviously shouldn't flag a lockout. maybe worth having a word with Firebird.
I also think I read somewhere that this post purge can be switched off.

EV's are normally tied in at the pump suction but I see some gas fired (combi?) boilers have it to the pump discharge.

 

[dave176]

Some low emission oil fired boilers now do a post purge after the burner shuts down, as well as the mandatory pre purge of 10 secs or so, this post purge obviously shouldn't flag a lockout. maybe worth having a word with Firebird.
I also think I read somewhere that this post purge can be switched off.

EV's are normally tied in at the pump suction but I see some gas fired (combi?) boilers have it to the

Some low emission oil fired boilers now do a post purge after the burner shuts down, as well as the mandatory pre purge of 10 secs or so, this post purge obviously shouldn't flag a lockout. maybe worth having a word with Firebird.
I also think I read somewhere that this post purge can be switched off.

EV's are normally tied in at the pump suction but I see some gas fired (combi?) boilers have it to the pump discharge.

could it be a problem with the actual burner control unit? when the boiler controls go into lock out the restart button on the burner control flashes green and red.

 

[dave176]

could it be a problem with the actual burner control unit? when the boiler controls go into lock out the restart button on the burner control flashes green and red.

the burner is a riello MO535 digital control box

 

[dave176]

the burner is a riello MO535 digital control box

Some low emission oil fired boilers now do a post purge after the burner shuts down, as well as the mandatory pre purge of 10 secs or so, this post purge obviously shouldn't flag a lockout. maybe worth having a word with Firebird.
I also think I read somewhere that this post purge can be switched off.

EV's are normally tied in at the pump suction but I see some gas fired (combi?) boilers have it to the pump discharge.

the boiler is about 10 years old, fitted in 2013. It's a indoor module. work that's been done so far to try and resolve the issue is a service, new expansion vessel but not the original type at the boiler. the plumber put it about 10ft away where the hot water tank used to be. when it was serviced the guy said he had to replace the fuel pump as he couldn't adjust the pressure to the nozzle and said there was a carbon monoxide issue. It also runs extremely hot ,doesn't seem to regulate the temperature, the burner doesn't cut out unless I actually turned it off so he then replaced the temperature control module. This wasn't cheap as it's a circuit board, he also changed the thermistor? one for the boiler, one for the hot water and a flow thermistor? but it still continuously runs until I switch it off. at this stage the pressure Guage reads 2.5bar I'm afraid to let it go any higher

 

[SimonG]

You need to bin off your oil engineer and get somebody in who knows what they are doing rather than just chucking parts at it.

 

[dave176]

You need to bin off your oil engineer and get somebody in who knows what they are doing rather than just chucking parts at it.

I hear you loud and clear. unfortunately I live in a very remote part of Ireland and can't get a definite day from anyone else to look at it and with the cold weather now set in and new born baby in the house I'm desperate, hence trying to get some answers here

 

[John.g]

You seem to have 2 problems here.
Combustion problem, a indoor model will take he air for combustion from outside, you might see a small hole in the wall underneath or above where the exhaust leaves the building, can you trace these and post a photo of your boiler front?. The combustion gases may be short circuiting the air somewhere, maybe at the boiler.

EV problem, what is the vol of the EV and how may rads have you got?