CO2 is the most important reading not the ratio?

[Gary80gas]

CO2 is the most important reading not the ratio? Statement from Valiant literature.
If this is correct then why is this not on the landlords safety certificate for example?
A landlords certificate requires gas rate and gas ratio co/co2 reading.
If these are both correct the boiler is deemed safety checked.

The co2 readings are sometimes lower than 9% in the MI. Am I contravening any gas regulations by not correcting it?

For example 7per cent instead of 9 percent in MI. I rang vaillant and they said its 'my call'.

 

[ShaunCorbs]

All the readings are important and they normally say a tolerance normally something like 5-10%

For me I would adjust if it's below or above 8.7 or 9.3%

 

[townfanjon]

Most manufacturers go straight to CO2 , but as Shaun says they are all important

 

[woodsy]

Rang Gassafe over this a few months ago and was told only the ratio is of any importance as far as they are concerned.

 

[GH77]

You could have on the money CO2, but if the CO was through the roof then you wouldn't just ignore it, the CO2, CO, O2, ratio, xs air and flue temperature will build you a picture of what's going on, I like to have as much information as possible on my screen when looking at fga

 

[Gary80gas]

You could have on the money CO2, but if the CO was through the roof then you wouldn't just ignore it, the CO2, CO, O2, ratio, xs air and flue temperature will build you a picture of what's going on, I like to have as much information as possible on my screen when looking at fga

I always gas rate the boiler, check input working pressure, then take fga readings. If the co and ratio look good im tempted to leave it working. Adjusting the co2 often takes the co out of limits. I check the flue integrity, if that's good what else can I do?
If the co2 is 2%below I don't want to change gas valves when the boiler is basically safe.

 

[ShaunCorbs]

If out of spec phone manufacturer up and ask them is it ok (just explain if you adjust it sends everything else out of wack)

 

[kris]

CO2 is the most important reading not the ratio? Statement from Valiant literature.
If this is correct then why is this not on the landlords safety certificate for example?
A landlords certificate requires gas rate and gas ratio co/co2 reading.
If these are both correct the boiler is deemed safety checked.

The co2 readings are sometimes lower than 9% in the MI. Am I contravening any gas regulations by not correcting it?

For example 7per cent instead of 9 percent in MI. I rang vaillant and they said its 'my call'.

I don't maintain much vailant but can't you adjust it to within limits, that's what I dislike about the ideal boilers is they aren't factory set to the cleanest burn and could be better and aren't adjustable,

 

[GH77]

I had a an Ecotec plus 831 on Thursday that was low on CO2 and Gas rate, I adjusted it until the CO2 matched the mi's, did the Gas rate again and it was within tolerance, CO was below 100ppm if I remember rightly ratio 0.0008, i'm not saying you should adjust, but i made an engineering decision

 

[kris]

I had a an Ecotec plus 831 on Thursday that was low on CO2 and Gas rate, I adjusted it until the CO2 matched the mi's, did the Gas rate again and it was within tolerance, CO was below 100ppm if I remember rightly ratio 0.0008, i'm not saying you should adjust, but i made an engineering decision

Yeh 0.008 ratio regulation for most flued appliances

 

[Gary80gas]

Rang Gassafe over this a few months ago and was told only the ratio is of any importance as far as they are concerned.

This dosent surprise me. If they made co2 the priority reading there would be more boilers with corrected co2 and left with higher co values. Ive corrected co2 and the co moves from 50 to 250 which always concerns me. I know im covered if ive hit the ratio. The Anton chart I use gives co2 allowances from 3.4 to 10.2 falling within the correct co/co2 ratio, so does this mean all these values are valid? No action required.