Central Heating System replacement advice

[PullerGas]

Thanks, I had been thinking I'd need a 25m with the 50m but was just going to pick it up as I go along. Not a massive trek to Wickes and the runs aren't massive. The manifold is pretty central and the rads are on internal walls around and beneath the manifold really. Any thoughts on JG speedfit pipe for central heating with compression fittings? Any other branded pipe worth looking at?

Speedfit will be fine (you'll almost certainly not be pressure testing to the required pressure for the warranty so it makes little difference what you use), use the layflat stuff to avoid getting too tangled up in the coils, and male sure you use the inserts without the o-rings on compression fittings. Personally I don't like compression on plastic, but then I generally avoid using either wherever possible. You'll use it up a lot faster than you realise!

100% agree.

 

[Random-Paddy]

Thanks for the posts PullerGas, yes that's along the lines of what I've been told. 10mm pipe, 8mm bore. I was hoping to go up to 15mm pipe, speedfit to allow water to the radiators faster and all going well they heat up faster (in theory, I realise there are other factors, happy for folk to point them out, more info is always better). Along with that fact, removing the acorn piping which may or may not last another 10 years means I know what's gone in and yes it may fail before the existing piping but at least I've more of an idea of its age and state.

My current plan is to
drain down the system, I fitted a drain off valve last year to one of the valves on the radiators downstairs as I had none to drain the system. I know where the filler tank is in the loft and will tie up the ballcock so it doesn't continue to fill.
1 by 1 I'll take a radiator,
Take it off the wall,
run the piping to the centre point of the radiator from the old manifold upstairs (not connecting).
Bring the pipes through the wall with the JG radiator outlet plate leaving plenty extra pipe to go to either side of the radiator.
bring the radiators outside and flush them through with mains pressure outside a good few times until they run clean
Re-hang the radiators through the plasterboard onto the brick, either with a baton behind the plasterboard or a proper fixing, they were all hung with self drill plasterboard fixings which don't take much to dislodge.
When the Radiators are hung solid, fit new Valves (not decided which TRV's to fit) these will go into a 90degree elbow compression fitting onto which the plastic pipe will connect (as per the image in my first post)
I'll repeat that for all the radiators that require to be rehung, all will be flushed.
Once complete I'll attach all to a new set of manifolds in the same location as the last and finally plumb back into the feed and return from the boiler.
I intend to have plenty ptfe tape and white jointing compound as required for the joints.
Once I've connected again, I'll refill the system from the filler, flushing it through the whole system and out once or twice to clear out anything left that I can get out.
Then refill for the last time with inhibitor.

After that, It'll be over to the plumber when I get one to fit a new boiler and tie into the manifolds with new pipework when the boiler is replaced. At this point I'd hope to have gotten rid of the hot water cylinder, the electric pump for the upstairs bathroom water feeds, the water storage tank in the attic, the central heating filler tank in the attic, the older still functional boiler in the kitchen and all the acorn 10mm piping in the house. The piping for water feeds in the bathroom upstairs was done a few years before we moved in with newer hep plastic piping so I do not intend to replace any of that, just have the new boiler plumbed into it.

If anyone wants to know why I'm getting rid of open vented and want a combi boiler, the reasons would be in the line of acorn piping and the reputation for it to cause failures or leak, the electric pump which causes a racket upstairs when you want water in the bathroom (baby on the way so would not be helpful), Almost instant hot water from a combi-boiler instead of trying to manage the timings for heating a tank of water (yes, that's laziness but my wife and I agree its just easier with 2 soon 3 kids and us), and really just because we can and its what we had before and it just worked.

Anyone who spots any flaws in my plan, feel free to point them out. Hoping to figure as much of this out before I start. Shopping list is being created so parts can be gotten in the month before's pay check in case it all goes wrong

Thanks

Paddy

 

[PK Gas]

http://www.plumbingproducts.ie/chro...chrome-327-compression-swivel-elbow-15mm.html

Are you using these to go from the plastic to the trv?

 

[Random-Paddy]

The link you posted gives a 404 error but that is the website I found the compression elbows on with the swivel. I would have hoped to get some local but not an issue to get from Ireland (clue's in my name as to why not).
Do you see an issue using them?
http://www.plumbingproducts.ie/chro...chrome-327-compression-swivel-elbow-15mm.html

I thought going from the usual chrome TRV to a brass compression fitting and then into a white pipe wouldn't look great. Also, I wanted the swivel end on the elbow so I didn't need a coupler or piece of pipe between the elbow and the TRV to make sure they are aligned when tightened.

Thanks

Paddy

 

[PK Gas]

Looking at the swivel fitting your thinking of using looks like it uses a washer sealing method but the trv will be a compression type with an olive

You may be better of with something like this

https://www.plumbnation.co.uk/site/...3PY-PCSTMZ9geEqLrdGj9ut9XaNgIrpYrwaAl1B8P8HAQ

This is what you showed in your first picture very common on new builds with 10mm plastic but also do a 15mm version for you situation

 

[Random-Paddy]

Eell spotted, hadn't thought about it. I'm trying to avoid the push fit fittings and have as few joints as possible. I may have to revert to a standard chrome elbow with a small piece of plastic or copper to the TRV. Any comments on whether that would work or if there is another solution outside of the above push-fit fitting?

 

[PK Gas]

What your suggesting will work

Any reason behind not wanting to use the push fit method as it will certainly look a lot better than what your suggesting?

 

[Random-Paddy]

I'm afraid of children's feet on the push fit fittings. I know they should hold if locked in place but ... I dunno. I agree, the push fit fitting you linked would be much neater and probably just work aswell. At the moment I'm making my shopping list and trying to think through any potential snags before I get started. It'll be May before I can get start due to other ongoings here at the moment. I'll have a think and price it all up. Could just aswell go for the pushfit ones.
Thanks
Paddy

 

[PK Gas]

If it makes you feel any better about it they are a b******d to get apart without the tool they have a locking ring type fit I've yet to see someone pull one out

 

[Random-Paddy]

Just out interest, have you fit any of these? I take it the other end from the pushfit end just sits into the TRV. Does it need an insert or just an olive over it and the compression nut?

 

[PK Gas]

Yes I've used these before with no issues

Insert in the 15mm plastic pipe push your fitting home and the other end into the bottom of the trv with nut and olive connection

 

[Random-Paddy]

Thanks. Now, what's next to pick apart.
Anyone got any comments on manifolds to use? I was looking at something simple, compression fitting, without any valves to reduce the possibility of something going wrong.
Sorry for basically asking people everything but I'd rather learn from other peoples experience than fall at the same hurdles myself.
Thanks

Paddy