Falcon II Boiler

[marziaabel]

Two years ago we had a Falcon II combi boiler installed and just recently it has started to make very loud banging sounds when the gas flame comes on (which is every 10 seconds) and the water runs very hot then very cold. So taking a shower is interesting!

We have had the problem looked at by 2 plumbers, 1 flue man and still no joy. Parts have been installed at great expense but still the problem persists, if not worse than when it started.

Any advice?

 

[DP]

Next time get a heating engineer. Is the central heating functioning correctly?

Who makes Falcon II boiler?

 

[marziaabel]

We have had a heating engineer look at it and they said there was a problem with the flue. The flue has been checked and there is no problem with it.

What next????

 

[AlanE]

Made by FER.

Ferroli supply parts aand manuals for the Falcon 2.

Alan

 

[DP]

Reading in between the lines, I am assuming CH is OK.

When the burner comes on, heated water has to be removed from the main heat exchanger otherwise the water will reach 100 degrees C and boiler will bank and rattle even with burner out, until heat has been dissipated.

I suspect the Falcon has a composite heat exchanger (secondary HE build into it).

I would initially be looking at changing/ checking the thermistor (CH and HW thermistors are identical if I am not mistaken- change them over and see if fault moves to CH.

Next monitor the temperature drop across the secondary heat exchanger. Expect 20 degrees differential. Greater temperature difference would indicate blockage

Flue problems can readily be identified by looking at the flame picture.