High gas rate on SIME Format HE. Possible cause?

[MarcusA]

Anyone familiar with servicing SIME Format 30HE? I had to shut down a boiler today as it was using far too much gas and I was unable to identify the fault. The CO readings were totally fine but the gas rate was coming in at around 38kW. Has anyone come across this before or have any idea what the problem might be?

 

[ShaunCorbs]

What was the co2 reading and how old was the boiler ?

 

[MarcusA]

What was the co2 reading and how old was the boiler ?

Boiler over 10 years old. The CO2 was at 8.7%CO2 and ratio was 0.0009. Under 100ppm. Usually when I get those readings the gas rate is slightly low and never high.

 

[Deleted member 120897]

How you doing the calcs? App? Anything overlooked, eg coming out of app?

 

[MarcusA]

How you doing the calcs? App? Anything overlooked, eg coming out of app?

Definitely nothing overlooked in terms of the app mate. I was using an imperial meter and it was taking around 27 seconds for the dial to move one full revolution. I tried multiple times with the same result. What’s even stranger is I was getting similar readings on heating mode when the boiler should be operating at a much lower output. It’s the first time I’ve experienced this with this boiler model so my brain is fried. I’ve checked for leaks inside and outside the boiler to no avail. A colleague suggested it could be a faulty regulator at the gas meter but I don’t see how that could affect the gas rate if the gas valve regulates the amount of gas getting to the burner.

 

[ShaunCorbs]

It could be a faulty gas meter did you note the boiler ramp down on heating ?

 

[MarcusA]

It could be a faulty gas meter did you note the boiler ramp down on heat

It could be a faulty gas meter did you note the boiler ramp down on heating ?

I’m starting to think it might actually be the meter Shaun. I didn’t not down the gas rate on heating but it wasn’t too far off the rate I was getting on hot water mode. There was a fire and a cooker in the property as well, I don’t know why I didn’t think on my feet and gas rate those to get rule out the meter. The meter is a very old imperial one so I suppose there could be an issue there. The appliances are in a social housing property, do you think it would be worthwhile getting the meter changed first?

 

[Deleted member 120897]

I don’t think you understood what Shaun was asking. When in CH mode, did the burner drop to minimum, as opposed to maximum rate in dhw?

 

[MarcusA]

I don’t think you understood what Shaun was asking. When in CH mode, did the burner drop to minimum, as opposed to maximum rate in dhw?

I did understand, that’s why I said there was no noticeable difference between the gas rate in heating mode and the gas rate in hot water mode, which is leading me to think the gas meter is at fault or something else I don’t quite understand.

 

[Deleted member 120897]

So the burner was at maximum? If so, then probably the boiler.