Add to existing combi system

[Garth]

Hello,

I have a combi boiler system with a double and a single radiator heating downstairs when it was installed the plumber left me with a send and return feed (22mm) going upstairs for extension. The time has come and have done plumbing myself but never on a combi system.

If someone could give me a rough guide on what I have to do to add 2 double radiators and a single into the feed that has been left it would be appreciated.

Mainly where do I go from the 22mm polypipeto 15mm copper and when opening the taps that isolate the upstairs feed to fill the system do you have to bleed the air from the radiators or is this done by the boiler ?

May be silly questions but I am confident to do it just want some professional advice !!

Thanks

Garth

 

[oldplumber]

Being confident isnt neccessarily the best reason for trying something when you clearly have no knowledge at all with what you are about to attempt. Best advice i am willing to offer is to call in someone with proffessional experience to ensure you dont wreck your home in the long term.

 

[Garth]

I think that reply is a bit extreme I understand what you are saying but would like to be certain for myself if I can do it or spend money I can't afford on a pro.

 

[Puddle]

You can probably reduce down straight way for only three rads upstairs,take one pipe from one of the pipe ends you have and attach to each right hand side of the radiators,to do this you will need to branch off pipe twice to two of the rads and continue on to the last,then do the same,from the other pipe to the left of each rad,fit thermostatic valves on all rads upstairs
When you come to fill ,turn off boiler and isolate power supply so you do not damage boiler and open isolation valves on pipe work ends you have connected to,refill system up to 1.5 bar at existing filling loop for boiler slowly,checking all the joints you have done,and vent new rads upstairs,if air stops coming out and also no water,top system up through filling loop again and so on until water coming out of all rad vents when venting,(hopefully this is only were water is coming out of)then double check system pressure at 1.5 bar and re-instate power to boiler and run

But old plumber is right,if you are unsure ,you could cause a lot of damage if a joint fails but if you have done some plumbing and take your time,thats your chose
good luck

 

[oldplumber]

My comments come from experience of attending callouts where someone likeyourself has had a go and I have to walk in on flooded carpets, a ceiling down and a wife pulling her hair out with the husband/partner away at work, having had a go at the weekend. Thed final costs can be quite a lot more than employing a plumber in the first place! Been there 3 times now, I only base my advice on experience gained after a few years in the job.

 

[Garth]

Thank you both for your help. I have very good experience in welding pipes together I just needed to be certain I had the right idea of how I needed to put it all together. You have done this for me and will get on with the job. I will let you know how I get on!

 

[Centralheatking]

I agree with the oldplumber - with the rise of plastic fittings etc. anybody can push fit anything together. A combi system is a heated pressure system which poorly designed/installed could cause
major damage.

centralheatking

 

[aggis]

If using plastic piping, remember to fit pipe inserts or else.......... everything will seem ok, then a few weeks later. Whoops the joints will part.

 

[Garth]

How much roughly would it be for plumber to do ?

 

[Centralheatking]

Its difficult to assess when the distances and other things are not to hand. 3 rads could be a days
work or a little more. You could supply the rads and fit them exactly where the plumber wants
them - that might save some dosh - then be there to see what he is up to
so maybe next time you can have a go.

centralheatking

 

[Garth]

Roughly 20 mtr to last rad with 2 in-between, um thinking of putting in and then getting plumber to check and fill system? How would that go down ?

 

[Centralheatking]

badly with some - others if their open minded it would be ok. I think thats maybe the best approach
for you.

centralheatking