Low Inlet Pressure

[AWheating]

If the pipework is undersized the fga readings are usually out.The inlet pressure for a wb 30 si minimum is 16.5mbar.

i have fitted quite alot of worcesters and still have not come across one that has a 1.5mb internal drop, i still seem to be able to get less than 1mb from meter to gas valve inlet test point.

do many of you find the same or am i just lucky??

 

[EPH]

i have fitted quite alot of worcesters and still have not come across one that has a 1.5mb internal drop, i still seem to be able to get less than 1mb from meter to gas valve inlet test point.

do many of you find the same or am i just lucky??

I go to loads of gas safety Certs and probably 10% have the right drop or within MI's.

 

[Mike Jackson]

I've had a couple but usually where they are on a seriously long gas run with lots of 28 or even 35.

To the OP, checking the inlet pressure at the appliance is completely meaningless without checking the working pressure at the meter. The requirement is for a maximum 1 mbar drop across the pipework, if you don't know what pressure it starts at you can't tell if the problem is the pipe size or the meter regulator.

 

[Destroyer2813]

i have fitted quite alot of worcesters and still have not come across one that has a 1.5mb internal drop, i still seem to be able to get less than 1mb from meter to gas valve inlet test point.

do many of you find the same or am i just lucky??

Not lucky must just be pipe sizing correctly

 

[EPH]

But the MI's do say min 18mbar in his defence.

 

[AWheating]

Not lucky must just be pipe sizing correctly

i normally run straight off the meter with 28mm as standard practice unless boiler is only 5m away on my own boiler installs. But i have seen it with pipe run on the limits shall we say and still less than 1mb from meter to valve. Makes me wonder what this 1.5mb lose is all about, i must just be lucky then i guess.

 

[Destroyer2813]

U order up a 28mm union or 22 with22-28 red soldered up on it

 

[Danv44444]

So if the pressures right at the meter and wrong at the appliance then the pipeworks undersized? if there both wrong then its the govener?

 

[Danv44444]

U order up a 28mm union or 22 with22-28 red soldered up on it[/QUOTE
Is there much difference in using a 28mm union or a 22mm union with 28mm reducer?

 

[AWheating]

So if the pressures right at the meter and wrong at the appliance then the pipeworks undersized? if there both wrong then its the govener?

meter wp should be 21mb +- 2mb, and then 1mb drop to the appliance. tho some boilers can have a pressure loss between its iso valve and test nipple which can be taken into account.

 

[AWheating]

U order up a 28mm union or 22 with22-28 red soldered up on it

i use a 22mm tail cus i get em for free. 🙂

the difference is not great.

 

[AWheating]

U order up a 28mm union or 22 with22-28 red soldered up on it[/QUOTE
Is there much difference in using a 28mm union or a 22mm union with 28mm reducer?

slight i guess, but gas is not restricted like water so wont make much of a difference overall.

 

[buckley plumb]

thats a big boiler to run on 22mm with a fire aswell . when doing terrace houses now i am fitting 28mm from meter at front of house and part way across front bedroom then 22m to feed 30kw boiler and cooker .

ant

 

[bright spark]

I'd go with snowhead. Check the standing pressure and working pressure at the meter. If its only 15mbar working pressure leaving the meter get gas supplier round as there a prob with meter. If the pressure is fine, around 20mb then the gas supply pipe is too small. Or there could be a slight blockage in the pipe. Could take out the filter on boiler gas valve incase there is dirt in it. Has been known to happen.