Biasi Garda m90f 32s Central heating problem.

[JonathanWright]

We always turn the heating on from the control knob on the front of the boiler, it always starts within a few seconds and the radiators heat up etc.....

Some time later we notice it is getting cold and when I look at the boiler it is sitting there with the fan blowing and the lamp flashing. If I turn the control knob to the off or * position and back up to where it was (say 3 for example) the boiler fires up and runs normally again may bee for a few more hours.

It seems as if it is getting to the correct temp but not restarting when the temp goes lower again....

Any ideas?

John.

 

[Agile]

The boiler has a fault!

If you are competent then open the small left hand cover on the top of the PCB case and see what the three lights are showing when the fault occurs.

It may show the fault code anyway or it may be necessary to move the right hand DIP switch down and back to get it to show the fault code.

It might be an NTC going open circuit when hot if you are lucky or it could be a faulty PCB !

Tony

 

[JonathanWright]

Thanks Tony
I've had the heating on all day today just waiting for the fault to happen, no luck yet.....

John



oo oo oo It's just done it.....

The middle and right hand lights are flashing...

Faulty NTC Sensor?

 

[Agile]

You are very lucky!

Faulty CH sensor!

Tony Glazier

 

[JonathanWright]

You are very lucky!

Faulty CH sensor!

Tony Glazier

Thanks Tony you are a star. I will order a replacement asap and post back with the results.

John.

 

[JonathanWright]

I have changed the temp probe and the boiler ran great for about four hours, I looked at the boiler and the light was flashing rapidly again and only the fan was running. Flicked the dip switch to get the fault code and now it is showing the left and right light are flashing together and the center light is on solid.

The manual says "Lack of burner ignition (no ignition signal from the full sequence ignition device)"
I don't know what to do with this code

Turn the boiler of and on and it appears to be working again.
When I look through the inspection window as the boiler ignites I can see a healthy blue spark between the middle and right electrode.

Any ideas?

John

 

[Agile]

Did you check the min and max gas valve settings and then the ignition pressure?

If it gives that display then usually the lockout light in the centre of the boiler will come on and be resettable by the red button beside it.

Tony

 

[JonathanWright]

Did you check the min and max gas valve settings and then the ignition pressure?

If it gives that display then usually the lockout light in the centre of the boiler will come on and be resettable by the red button beside it.

Tony

Tony thanks for taking the time to reply.

Not sure how to test the min and max gas valve settings but the lockout did not come on.

John

 

[Agile]

No, I am very sorry I had a momentary glitch as that instruction is only for the CORGI registered !

When the boiler lights does it light promptly across the burner in both directions?

When the burner is on minimum, either with minimum hot water flow or by removing one wire from the mod coil on the gas valve, then how big is the flame? Will it run forever with a mod coil connection off or does that cause it to go to the flame lockout?

Tony

 

[JonathanWright]

No, I am very sorry I had a momentary glitch as that instruction is only for the CORGI registered !

When the boiler lights does it light promptly across the burner in both directions?

When the burner is on minimum, either with minimum hot water flow or by removing one wire from the mod coil on the gas valve, then how big is the flame? Will it run forever with a mod coil connection off or does that cause it to go to the flame lockout?

Tony

It does light promptly across the burner in both directions

Burner on minimum? I ran the hot water with just enough flow to fire up the boiler and it lights (with the same size flame as when on full flow or when the heating is on) the boiler runs then stops for a few seconds then fires up again, it does this process over and over for about 10 min without a fault showing (I assume that is normal).

John.

Which wire do I remove from the mod coil?

 

[Agile]

It sounds as if the gav valve may be a long way out of adjustment!

There is a blue mod coil at the top of the gas valve. Remove one connector and the flame should drop to a small height!

Tony

 

[JonathanWright]

It sounds as if the gav valve may be a long way out of adjustment!

There is a blue mod coil at the top of the gas valve. Remove one connector and the flame should drop to a small height!

Tony

Tony
I removed the wire and tested as before and the flame size was the same....

I followed the wires back to the PCB and found that the plug was not on properly, it was sitting at an angle. I have pushed it back on and retested. I now can see a difference in the flame size when on low flow and high flow.

Guess we will see how it runs today.....

 

[Agile]

One might wonder who had disturbed the PCB plug.

However, it sounds as if your gas valve is still not set up correctly.

Whilst I could tell you easily how to set it more correctly in about 10 secs without any test equipment, it should in theory be checked by a competent boiler engineer.

I would get criticised if I told you on an open furum and my posting ought to be deleted for giving inappropriate advice. Having said that the mods here seem to have an odd idea of what to delete or not.

Tony

 

[JonathanWright]

One might wonder who had disturbed the PCB plug.

However, it sounds as if your gas valve is still not set up correctly.

Whilst I could tell you easily how to set it more correctly in about 10 secs without any test equipment, it should in theory be checked by a competent boiler engineer.

I would get criticised if I told you on an open furum and my posting ought to be deleted for giving inappropriate advice. Having said that the mods here seem to have an odd idea of what to delete or not.

Tony

When the boiler was installed about 4 years ago, the CORGI guy could not get it to run, it would run for a few seconds and the switch off. He was on for hours and he did remove the PCB and then put it back, he failed to spot the flow sensor for the hot water was not attached properly. I "had a look" when he left and put the sensor on correctly and it has ran like that since.
So it looks like it has not been commissioned properly i.e. setting up the gas valve.

I appreciate your help and advice and I would not want you to get in bother with the mods. You could always send a message if you like.


John

 

[JonathanWright]

Well 24ish hours later and it is still working, thanks to Tony's advice.

Do you think it would be advisable to get someone in to check the gas valve settings are ok? also will we have been using too much gas by it not been setup properly in the first place?

John