Help Needed With Biasi Garda M90F.32S

[paulw01]

Ok the boiler is about 4 years old, what's been happening is that when the boiler is on standby (no hot water or ch called for) the boiler keeps on going through a sequence of trying to fire up and shutting down, when it does this the green led on the left hand side of the control panel flashes very quickly.

The central heating seems to work normally but the hot water runs cold if the tap is opened to more than a trickle, sometimes though when the green led decides to flash normally the hot water works great with the tap fully open !

Any ideas as its driving me nuts ??

Thanks in advance

Paul

 

[Agile]

I would hazard a guess that your DHW sensor is intermittent. Replace it and see if that sorts out the DHW issue.

The random firing might be as a result of the above causing a frost protection action. But see what happens after the sensor is fixed.

Tony

 

[paulw01]

I would hazard a guess that your DHW sensor is intermittent. Replace it and see if that sorts out the DHW issue.

The random firing might be as a result of the above causing a frost protection action. But see what happens after the sensor is fixed.

Tony

Tony, DHW Temp probe (sensor) has been ordered, will let you know if it has fixed the faults when fitted, cheers paul

 

[paulw01]

Well was a bit bored this morning so decided to get my digital mutimeter on both the DHW & CH temp probes, it would appear that you were right Tony as this sensor is totally open circuit / intermittent which would activate the frost protection, as a test I got a variable resistor and set it to 5000 ohm which equates to approx 45 degrees centigrade, plugged it in place of the sensor & the boiler worked faultlessly, the hot water worked a treat, however for safety reasons have put the plug back on the faulty DHW Sensor and await the arrival of the new part.

Thanks again

Paul

 

[Agile]

Set it to about 25k - 35k and it should bring the boiler on in frost protection mode!

As you obviously have a good understanding of what you are doing it would not bother me if you put a 4.7 K resistor across the DHW sensor and it will give you passable DHW until the new part arrives.

Happy new year!

Tony

 

[paulw01]

Yes might try that as it is painfully slow when your trying to fill the bath, might be able to sleep better too as the boiler is upstairs and has been driving me mad of late while its been going through its start up process every few mins.

Thanks again Tony & Happy New Year !

Paul

 

[paulw01]

Just an update, the new sensor arrived Friday for the DHW, the hot water now works a treat and does seem to work better than when the boiler was new, it possibly could have been faulty from day one ! The boiler has also stopped cycling so can now get a decent nights kip !


Thanks again Tony for your advice, it was spot on !

Cheers

Paul