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Gas install boiler questions
mark chandler - 13/3/11 at 09:38 AM

Hello

I am throwing out the economy 7 and putting in a gas boiler and rads, the house now has a new gas supply so will be plumbing in, do I need the boiler working for the corgi man to sign off the install?

The reason I ask is that tanks, immersion and header will be coming out so although I can plumb in the heating circuit I do not want to be without hot water so want to install to this point make the connection and get tested.

Bonding, how fat do the earth wires have to be?

Drain taps, I noticed some houses have these on all rads, is this a requiremnt these days, before I just had one at the lowest point?



Cheers Mark

MikeR - 13/3/11 at 09:56 AM

Having a drain on each rad means if your water supply comes from above (as in my house - all services in the ceiling) you can drain a radiator / clear the whole system.

I'm no plumbing rules expert but ..... I think if you plumbed in the boiler & hot water and had that tested you'd be ok. You can then add / remove radiators as required. Adding radiators isn't notifiable like electrical work.

Having said that, I think you may need to plumb in one radiator so the heat from the boiler has somewhere to go. No evidence of this, just seems strange not to do it to me.

BenB - 13/3/11 at 10:09 AM

I'm pretty sure they have to test the gas pressure at the boiler when it's on full chat to make sure that the gas pipework isn't knackering gas pressure. Certainly on my install I install the CH and DHW pipework and fitted the boiler the wall and Mr Corgi soldered together the pipes I'd cut and put in place and then he tested it. He was very adamant that he had to test it on full chat. On my boiler there's a function which puts the CH and DHW on full guns but of course that does mean at least one radiator.

Macbeast - 13/3/11 at 10:10 AM

AFAIK a central heating system has to have one radiator permanently open ( usually the bathroom ) to allow circulation of heating water at all times.

BenB - 13/3/11 at 10:25 AM

quote:
Originally posted by Macbeast
AFAIK a central heating system has to have one radiator permanently open ( usually the bathroom ) to allow circulation of heating water at all times.


Doesn't have to if you fit a pressure-bypass valve between the boiler outlet and inlet. In fact I think that should be done in addition to having a non-TRV radiator (usually the towel rail) because even with a cover-locked towel rail valve there's nothing stopping someone from closing it off and causing an over-pressure.

Then again, most boilers (? all) have a built in excess pressure vent.

fishywick - 13/3/11 at 10:29 AM

quote:
Originally posted by Macbeast
AFAIK a central heating system has to have one radiator permanently open ( usually the bathroom ) to allow circulation of heating water at all times.


Although some boilers have this function built in.

Also as of 1st April 2011 boilers must be Sedbuk rated A. there are still plenty of B rated boilers on sale which the Corgi/Gas Safe man won't sign off after April.

And as others have said I'm certain he will want it it working.

eccsmk - 13/3/11 at 10:29 AM

the gas supply needs to be tested before and after installation by a gas safe registered engineer.
also the connection at the boiler end must be done by a registered engineer so as they take responsibilty for the gas pipework
or thats how i work with other contractors.
you dont need to leave one rad with lockshields on as a bypass can be fitted link

if you need any advice please feel free to send me a u2u
hope ive been of some help

mark chandler - 13/3/11 at 10:31 AM

You can solder all the pipes, they pressure test but I was not aware that they need to run the boiler?

My dilemna is that to complete the install without gas connected I have to remove the tanks so will lose all hot water in the house until someone trots along.

The system will have a towel rad, the boiler has excess pressure stuff.

Regards Mark

slingshot2000 - 13/3/11 at 11:52 AM

Bonding, gas; must be a minimum of 10.0mm(squared) and must be within 150mm of meter and BEFORE any joints or branches.
Bonding, water; must be a minimum of 10.0mm(squared) and as close to main stop tap as possible. Hot and cold must be cross bonded with same size cable, usually under the kitchen sink.
Bathroom radiator MUST be earthed, even if plumbed with plastic pipe.

Some gas fitters (Gas Safe now, Corgi lost the job sometime ago) insist on cross bonding of each pipe just below the boiler.

Hope this is of help.

Regards
Jon

[Edited on 13/3/11 by slingshot2000]

deanwelch - 13/3/11 at 12:46 PM

the most important thing is that you have got someone that is prepared to sign the job of for building control and your boiler warranty............as most engineers wont sign off someone elses work ie gas pipe / sleving / electrics / system water quaility / boiler protection / flue connection / access / termination and many more things as they then become responsiable for all faults on system and when they register the job online the information goes straight to the tax man...........................................hope this helps..................drain offs on rads are the least of your problems