Old non condensing boiler

[Sue66]

Hi I'm newly qualified. Why would a boiler be 23mb at the meter on working pressure and 19mb at boiler inlet pressure and 14mb burner pressure. This is fine as per the MIs but i thought there was only supposed to be a 1mb drop.

 

[ShaunCorbs]

Restriction of the gas valve you can loose 4-5 mbar on a gas valve

Also some burners are reduced in pressure and you can set them (not the same as inlet)

But inlet pressure seems low you done a quick gas pipework calc ?

 

[Sue66]

There is about 4 meters of pipework to boiler mostly in 22mm. I thought it was low. I have gas safe inspecting me so I'm trying to get my facts straight. Its a Worcester 28i RSF. The other wierd thing is the co co2 ratio is 0.0003 and the MIs say it should be 0.003-0.007. Its really low. The gas rate is perfect though.

 

[Sue66]

And Shaun thank you you are right the MIs say that it's preset to about 13.5mb so that bit is bang on.

 

[ShaunCorbs]

would do it old school and just have a look at the ppm on the fga

(old school)

flame picture, burner pressure, gas rate

and gas pipework sounds ok, other than the inlet filter to the gas valve being slightly blocked it should be ok

 

[Sue66]

Ok that's really helpful. Thank you for your time. 🙂

 

[Sue66]

Would it also be worth mentioning there is a 2mb drop off pressure on the installation that is apparently untraceable. Within the 4mb permissible limit with no smell of gas.

 

[ShaunCorbs]

what meter is installed?

and did you isolate the boiler?

 

[Sue66]

G4 meter.Yes i tried isolating the boiler and it made no difference there is a 22mm pipe that Ts off and goes underground to the cooker. I have yet to cap off either direction to find out which route is responsible for said drop in mb.

 

[ShaunCorbs]

any gas fires?

 

[Sue66]

No gas fires just the cooker and the boiler upstairs. Actually it goes underground in 28mm comes out the wall behind the cooker.

 

[Sue66]

 

[ShaunCorbs]

looks like steel pipework in the ground

 

[Sue66]

Ok that does not sound reassuring but helpful all the same. Ill wait till the gas safe guy comes and then fix it. I don't really know if he can penalise me for having a numpty gas installation prior to my qualifying.

 

[Sue66]

Thanks for your input Shaun.

 

[ShaunCorbs]

aslong as you have an ok drop you will be fine and steel pipework is better than copper in concrete

 

[Sue66]

Ok thanks mate. These inspections are scary when your newly qualified and i keep finding abnormal stuff lol. Just my luck!

 

[ShaunCorbs]

You will be fine there only there to check your working safely