Biasi M296.28SM/C hot water fault

[abc_plumb]

Hi Guys

Need some advise here.
Went to a property today which had a Biasi Riva Plus He M296.28SM/C.
The problem is the burner goes off after 2 mins then back on again on hot water mode.
When the burner goes off, the 1st (far left) green led is flashing the middle red led is flashing and the (far right) green led is solid.
The manual suggests a faulty APR.
but after 19seconds the boiler fires back up for couple of minutes, and goes through the same cycle again.
The DHW plate is clean, and the gas pressures are good.

When I took the combustion chamber off the burner didn't go off.
This is all making me think its the APS, but the above fault doesn't happen on heating, which is putting me off.
Any experts out there on this boiler?
Your help is appreciated.

 

[CES]

Can you post this in the GSR private forum? You will get more responses in there.

 

[abc_plumb]

Sorry I thought I did??
How do I do that then?

 

[abc_plumb]

Sorry I thought I did??
How do I do that then?

 

[CES]

No, you're in the Central Heating forum. PM Bod or System3

 

[Mr Doberman]

Sorry I thought I did??
How do I do that then?

You dont I do...thread moved.

 

[abc_plumb]

Ok thanks.

Now that this is in the correct forum, does anyone have any suggestions??

 

[buckley plumb]

sent my mate to one doing the same as i was busy will tell you waht he found when this is in the gsr section

 

[dancinplumba]

sent my mate to one doing the same as i was busy will tell you waht he found when this is in the gsr section

it is ant 🙂

 

[lame plumber]

going off only on hw demand ie max rate, so aps could be failing, fan could be failing on max demand, sensor failing on dhw side check its resistance, blocked air inlet flue, restricting air flow giving aps reduced air flow hence why it cuts off but recovers ok when you open combustion chamber cover. few ideas to go on there.

 

[buckley plumb]

he found a blockage in the flue venturi also the inner flue had come apart slightly . remove venture and clean and check integrity of flue as alredy stated on the post.ensure correct fall on flue

 

[abc_plumb]

Cheers guys,
Will have to go back there.
I was waiting for the Air Pressure sensor, good thing they didn't have in stock.

 

[abc_plumb]

Went back here, cleaned the fan and venturi.
flue is well secured and sealed on both sides.
I even poured water down the flue to clean and derbies in the heat exchanger.
None of this worked, boiler was doing the same. 🙁

 

[buckley plumb]

Went back here, cleaned the fan and venturi.
flue is well secured and sealed on both sides.
I even poured water down the flue to clean and derbies in the heat exchanger.
None of this worked, boiler was doing the same. 🙁

just before it cuts out what temp does it show on the temp gauge.

 

[abc_plumb]

Didn't really notice that, but I did remove the domestic heat exchanger and it was really clean.

 

[buckley plumb]

Didn't really notice that, but I did remove the domestic heat exchanger and it was really clean.

i would be tempted to try a new aps, or if possible temp short old one and refit cover to see if it stays on - check thermistors and diverter