Potteron Lynx Help!!!!

[Gasguru]

Coz the guy that doesn't mention it is either incompetent or he's cutting corners (and probably not notifying) in order to undercut the conscientious installers.

Thats why I no longer do installs - too many cowboys in London not doing the job properly.


Did anyone mention part L - TRV's on bedroom rads, room thermostat, condensing (unless survey proves otherwise), GWN, powerflushing etc

The installation must comply in every way with current regulations, older boilers happily ran on undersized gas pipework (within reason), however modern boilers (typically with pre-mix burners) are often less tolerant.

 

[doitall]

Ive literally just had another CORGI guy come take a look to give me a quote and he didnt even mention it??
I dont understand how two apparently CORGI guys would have different opinions?
is there no way round this 22mm rule??

There is no 22mm rule the pipe is sized according to length + number of bends + gas rate of appliance.

Boilers I'm installing at the moment require a 2" gas supply.

 

[alexmack2006]

yeh the guy who mentioned the pipe size mentioned thermostat rads and the vallient condensing boiler that he would fit.
He also said the pipe may be 22mm to the boiler but the final peice was 15mm. he outlined that digin up the bathroom floor in an attempt to find the pipe would be the best start before he would fit a new 22m pipr direct from the boiler.

If i used the other guy who wouldnt change the pipe from 15mm, what would happen??

 

[Gasguru]

Is there no alternative route for the pipe? - across loft, round the outside wall?

The other guy is installing the boiler illegally.

It may work or appear to work correctly to you with an undersized pipe. However some boilers are more intolerant of undersized pipework and typical problems are failure to ignite on startup and lockouts (which require the boiler to be reset). The boiler may not produce its specified heat output.

Remember Transco (or whatever they are calling themselves this month) normally supply gas pressure at 21mbar ±2 at the meter outlet. The gas pipe is sized to allow a maximum drop of a further 1 mbar to the boiler.
Therfore the boiler inlet pressure should be between 18 and 22 mbar.

Some boilers require pressure close to this lower limit to operate correctly.

The legal minimum gas pressure from Transco can be down to 14mbar. This does happen in some areas due to poor pipework in the road (so the pressure is reduced), water in the pipework or high demand at peak times.

Any problems with the supplied pressure will be compounded by undersized pipework to the boiler.

 

[alexmack2006]

I also assume that if its fitted illegally this invalidates any warranty??
Thanks for your help

 

[Gasguru]

Well there's no point in calling out the manufacturer when you start getting lockout error codes !

 

[Agile]

"""The legal minimum gas pressure from Transco can be down to 14mbar"""

Is this written down anywhere?

How does it sit with the CORGI edict that a low gas pressure of 16 mB (?) is classed as "At Risk" ???

Many of the band A boilers stop working properly at 17 mB !

Tony

 

[Gasguru]

This has been told to me by Transco management.

Some roads in Mitchum, SE London are notoriously low pressure.

Corgis view (when I have enquired) is providing hob flames etc don't extinguish on boiler fire up its acceptable to leave.

Makes a mockery of gas regulations, since when this this industry make any sense.

 

[Agile]

If you fitted a boiler there CORGI would classify it as At Risk with 16 mB inlet pressure.

If Transco supply 15 mB at the meter, CORGI say thats alright !

Could it just be that CORGI just dont want to take TRANSCO to task ???