DIY Plumbing Dilemma

[pja123]

Just moved into my new home, and one of the first things that needed looking at was the heating system.

To start with most of the radiators have rusted up and split on the bottom, i've basically replaced the lot today, so 8 radiators measured up and hung.

Floorboards are up and it looks like there is a main run 15mm running down the landing splitting off into each room in 8mm microbore, what i've noticed though is that most if it comes up at old angles around joists and more often than not comes up to the radiator through the skirting boards!!!! Surely this isn't normal practice?

Anyway, my question is i want to do away with the microbore in favour of 15mm pipe up to the rads nice and neat. However i've never done any copper soldering/plumbing before but i do fancy a go - the furthest run from the main run of 15mm on the landing is about 7 metres (most are about 5 metres).

With that in mind (nil copper experience), do you think i should go the plastic route instead and speedfit the routes entering each room and come up with copper tails?my intention is to do this once and forget about for the next 20 years or so.

The plastic option seems to be the easiest option, just worried i'll be having the floor up every couple of months replacing fittings and seals etc - is there anyone out there who's done a similiar thing, what did you use? Plastic seems cheaper, and quicker - albeit less reliable????

 

[1john]

I think you will need to up the 15mm main lines to 22, plastic is fine, we put al plastic in a friends house he renovated over 2 years ago and no problems what so ever, we used hep2o fittings and pipe, the pipe seemed much more flexible than the john guest, which may help you out.

 

[pja123]

I should have mentioned the first 1.5 metres of pipe dropping from the boiler to the floor are in 22mm, it reduces down to 15mm and runs for another 2-3 metres in opposite directions across the landing before branching off into each room in 8mm.

I'll have a look at the HEP stuff, don't see much of it about to be honest.

 

[gblades]

If you are going the plastic route the normal way to do it would be to take the 22mm from the boiler into a manifold and then run the plastic pipes from the ports on the manifold to each radiator.
Drop the 15mm pipe from the radiator under the floorboards to an 90 degree angle and then a compression fitting to the plastic pipe. Just make sure you use a compression fitting which is designed to be compatible with plastic pipework and that you use the correct inserts with the plastic pipe on the compression fittings.

 

[pja123]

Thanks for that, i've just noticed that none of the existing microbore is supported when it runs parallel to the joists, should pipe work be tacked/clipped to the joists? Presumably the microbore doesn't carry much load weight so it was acceptable not to do this? I have to say though, from an unexperienced eye, the more i look at the existing stuff the more i'm starting to think it's been fudged in from the start, in some areas the joist notching seems completely unnecessary a third deep in some cases.

Some of the new rads are gonna be a pain to connect up as well, just realised that two hang directly over the joists making a straight connection from below a pain, don't won't to notch where i can help avoid it by any means.

 

[mickyg]

where the pipes drop onto a joist is where soldering becomes king. A neat soldered elbow will require a much smaller notch than a whacking great big plastic fitting. I wouldn't however recommend soldering a whole heatin system to a novice unless you've got plenty of time and patience.
There are some plastic type pipes available that require crimped fittings that I feel much more confident about long term, however these require special tooling which may seem overkill for a one off project. I prefer JG speedfit for general plastic(use collett clips and inserts) but as said the pipe lacks flexibility especially when cold.

 

[gblades]

Also note that some manifolds have isolators on each output which can make things much easier if you ever want to disconnect (moving a radiator for example) as you can leave the heating on and just drain the individual radiator.

 

[ChrisR]

Manifolds are usually only used for under floor heating, or microbore. I suggest you ditch the microbore, and the manifold idea.
DIY abortion manifolds often have 27p valves as isolators, which are certain to leak after a few years. It's madness to put any valve under the floor, especially at a manifold.

Come off the boiler in 22mm copper. 15 mm is OK for up to about 4kW, for several reasons you don't really want to be feeding more than that. So you almost certainly will still need 22mm after the first tee, on one branch at least.

At 22mm, plastic is easier if you use straight lengths. If fact long straight lengths are often easier in copper. It's common to start with copper then go off in 15mm plastic. If you want smaller push-fit fittings, these are quite neat:
http://www.pegleryorkshire.co.uk/en...2318&Rid=e0fca590-bb37-4c9e-a9a5-ea802428a640

joist notching seems completely unnecessary a third deep

That's in direct contravention of the Building Regs, apart from common sense.
Yes all pipes should be supported. The smaller they are, the more frequently.


Get someone to show you soldering of copper. Not hard to get right, but orribly easy to get wrong.

 

[herebriefly]

Manifolds are usually only used for under floor heating, or microbore. I suggest you ditch the microbore, and the manifold idea.
DIY abortion manifolds often have 27p valves as isolators, which are certain to leak after a few years. It's madness to put any valve under the floor, especially at a manifold.

Come off the boiler in 22mm copper. 15 mm is OK for up to about 4kW, for several reasons you don't really want to be feeding more than that. So you almost certainly will still need 22mm after the first tee, on one branch at least.

At 22mm, plastic is easier if you use straight lengths. If fact long straight lengths are often easier in copper. It's common to start with copper then go off in 15mm plastic. If you want smaller push-fit fittings, these are quite neat:
http://www.pegleryorkshire.co.uk/en...2318&Rid=e0fca590-bb37-4c9e-a9a5-ea802428a640

joist notching seems completely unnecessary a third deep

That's in direct contravention of the Building Regs, apart from common sense.
Yes all pipes should be supported. The smaller they are, the more frequently.


Get someone to show you soldering of copper. Not hard to get right, but orribly easy to get wrong.

Hear hear.

 

[pja123]

Thanks for your help and insight guys, it's much appreciated. I've started already in copper and the first run to the back bedroom radiator is done now - pretty much a straight run with only two bends (round a corner, then up to meet the radiator) on each of the flow and return pipes (start with easiest first!!).

I've been a little bit over zealous with the solder, more out of paranoia than anything, but once cleaned up they don't look too bad.

I bought one of those autocut pipe cutters, tiny little thing but surprised how well it cuts, 3 quick turns and job done.

In terms of testing for leaks should i fill and drain the system for each new branch ? I was going to get all the piping in say for one floor then fill, test and drain, then proceed in that fashion?

I'll get some pictures up soon, so you can have a good laugh at my work

One other thing, when it comes to flushing and cleaning the system how long should the cleaner be left in the system to circulate and do it's job? Which cleaning product would you recommend?

 

[gblades]

Its probably easier to do all the pipework and then fill and test. You cant re/desolder a joint if there is water in the pipes so having to completely drain the system is a pain. A wet vac can be very usefull for sucking the water out of the pipes.

Also bear in mind that the copper pipe will expand when it gets hot. So if you have a long run include a gentle bend in the length of the pipe so the pipe doesnt push against the radiator which could cause it to creak as it gets hot.

 

[pja123]

I've noticed that a couple of the end joints i soldered tonight had small globules/slivers of solder form on the inside, i think i might be over doing it on the flux if the solder is running right through and collecting on the inside, or perhaps too much heat?

Very conscious all the time of overdoing it on the solder though, as soon i see the flux start to boil a tiny bit and the flame go greenish i take the heat away and run around the joint with the solder, i'm using fernox powerflow, trying to get the heat spread evenly around the joint where i can too.

In terms of flushing the system, i was going to fill the system with x400 cleaner, leave for 24 hours, take a rad off and flush any small debris out that way - any suggestions?

 

[Andygasman2010]

So are you doing it all in copper now? Personally i'd say that's the best way. To take copper out and install plastic is madness to me! I find plastic just gets sludged up, even the barriered stuff. Anyone else experienced that?

Don't worry about too much solder, so long as it don't leak! You're cleaning out excess flux anyway so that shouldn't be a problem.

plastic expands alot more than copper when hot.

Never put any valves under the floor, or anywhere they're not absolutly necessary to be honest! They WILL at some point in their life leak.

Soldered copper everywhere is best, compression only at rad valves and boiler connections.

I've got lots of bad experiences with plastic so maybe i'm biased, i'd even go for microbore over plastic. i mean, an average system so long as it's inhibited and configured/balanced propperly works perfectly well on 8 or 10mm.

What does everyone else think about plastic?

 

[mickyg]

What does everyone else think about plastic?

its fine if properly installed and looked after...which is erm......never

 

[Andygasman2010]

Hmm yea that's what i seem to find. i had a 22 rad system with problems the other day, top two floors were fine but downstairs had been renovated and plastic had been used. There was pretty much no circulation at all downstairs! managed to get a flush machine directly on the downstairs circuit (upstairs isolated) managed get s**t loads of carp out but it still didn't work proppery. looks like it was furred up throughout its length. All fitted under expensive hardwood flooring! oh dear....