Ideal Logic - low gas rate causes

[cascas]

Hi,

This is the first 30kw logic that I have fitted this one is giving me that is giving a low reading on gas rating. It is measuring 2.94m3/hr compared to 3.13m3/hr in the MI. - checked more than once.

Inlet OP pressure measured on the test point is 18.5mbar, meter OP is 21mbar. Ideal have already confirmed that the reading on the test point gives a result 1.8mbar lower due to internal losses. There is therefore <1mbar loss on the pipework.

I have asked Ideal to confirm tolerances for gas rate, who advise that the rate should be as MI, but "as a rule of thumb allow +/-5%". I have asked ideal to advise of possible causes for a low gas rate (not adjustable), and they have replied to refer to the following page of the MI (as below), which I cannot see as being helpful. Surely, if inlet pressure is OK, then it not a pipe sizing issue?

My feeling are that it has to be fan related, and the the boiler is modulating to keep FGA readings ok, or is it close enough not to worry about.

Does anyone have any ideas before I talk to ideal again.

Cheers.

 

[SimonJohns]

I think your over thinking this. It's not that far out

Have you done a FGA to make sure it's burning proper

 

[gasmarc]

Check a previous thread last week with this exact problem so dont sweat it imho