Baxi Megaflo 32HE fault

[Robert Tyrrell]

Hi guys - went to a call on Saturday where the boiler was showing the E133 ignition fault code and noticed that the pressure of the system wasn't right as it was rising when I reset the boiler, and got it to fire.
I adjusted the pressure to 1.2bar and it fired but the pressure then rose to around 0.5bar.
It fired and worked fine but apparently this morning he had the same problem again so I went and did the same thing. Now he's saying that it's happened again.

I diagnosed a faulty vessel and told the customer that I'd be back on Monday to sort it as I didn't have one on the van.
In the meantime he's contacted BAXI and their engineer, over the phone, has come up with a different diagnosis in that he reckons it's a valve. He didn't specify which valve just that its a valve causing the problem and not the vessel, and that they could get an engineer out to him on Monday.
From my experience, in cases like this with the pressure being low and then rising on ignition, it's always been a faulty vessel so do [they] know something that I'm missing, and do any of you know which valve they're talking about? I suppose it could be a pressure switch though.
I'm presuming that it's the prv, and they think it's letting by but that doesn't explain the fluctuation in the pressure values.

 

[Billy Bob Bob]

By the gauge moving,this can give a false reading,pump pulls on it,can be misleading ,other than a prv,no other valves in a megaflow system,its basically a system boiler Duotec

 

[ShaunCorbs]

think they mean a filling loop

 

[Robert Tyrrell]

By the gauge moving,this can give a false reading,pump pulls on it,can be misleading ,other than a prv,no other valves in a megaflow system,its basically a system boiler Duotec

Thanks, that is is what I was thinking, hence the statement:
"do [they] know something that I'm missing, and do any of you know which valve they're talking about? "

 

[Stoney Ground]

Thanks, that is is what I was thinking, hence the statement:
"do [they] know something that I'm missing, and do any of you know which valve they're talking about? "

I would invoice for my time, if he had not paid on the day and let Baxi sort it for him.

Had similar with a duotec, put cleaner in for a week or so then drained and refilled all was fine. Bugger to get to valve on expansion vessel.

 

[Gasmk1]

does it have a flow switch ? is this the valve they mean

 

[Robert Tyrrell]

Cheers guys - I've asked him to get BAXI to sort it for him as I haven't got the time anyway. I also asked him to get a specific description of the fault from the BAXI engineer so I can record it for future reference.
Decent customer, he's already asked me to invoice him for the time I've spent, and to arrange to go and service it for him

 

[Robert Tyrrell]

does it have a flow switch ? is this the valve they mean

According to the short parts list there isn't a 'Flow Switch' that I can see, just an NTC sensor on the return.

 

[Billy Bob Bob]

According to the short parts list there isn't a 'Flow Switch' that I can see, just an NTC sensor on the return.

No definitely no flow switch,it works by looking for a balance in ohms readings between flow and return ntcs,if the ohms reading or temperature difference is not in spec the pcb would shut it down,in this boilers case most likely causes would be a faulty pump or blocked return filter,using a return ntc negates the need for a flow switch