DIY Central Heating

Jeepers_Creepers

Boiler / System 3 days for a DIY novice? Good luck :-)

Refilling Yes, I would simply refill (not 'repressurise' - that's a term for 'sealed' systems) the system with water to test, and also it'll clean away any flux and stuff when you drain it down again. Only when you are 100% certain it's all fine do you add inhibitor. You can also get 'new system cleaners' designed to remove flux and other nasties. Don't know if that's worth it.

Blow Torch I had planned on getting a Rothenberger SuperFire 2! Seems to be the go-to in the industry. Sounds good.

Using PTFE tape I was jesting. In earnest. Give it enough turns to nicely coat the thread. If that's 10, so be it.

Valves I had planned to get Drayton TRV4 valves. Anyone have experience with these? They are a standard fitment on lots of jobs. They should work perfectly well.

Solder joints vs compression fittings vs push-fit fittings Yes, comps are much bulkier, far more expensive, and probably more inclined to weep over time than soldered joints, tho' they should be reliable when done properly - which is the key to soldered joints too, of course. Definitely not good to look at. If you do use them anywhere, then I always - personally - give both the olive and the thread a smear of Hawk White. It not only ensures a seal, but also lubricates the thread which can turn a stiff and screechy comp into a smooth-running dude when tightened. 

Has anyone had experience with copper push-fit fittings? These could very well be the best solution for ease of installation and aesthetics. Tacpot12, noticed you mentioned you had used these a small job. How were they? Any issues? I've used them on some occasions where I wanted the benefits of push-fits - mainly that they can rotate! - but also wanted them to look neater than plastic when used on copper pipe (eg, under my kitchen sink where they could be seen when cupboard opened). Definitely much nicer and neater than plastic and comp fittings, tho' not as neat as soldered. Expensive. Same to use as plastic push-fits; on copper, you MUST de-burr the pipe end and ensure it's round or else you risk the O ring being damaged.

10mm pipes Jeepers_Creppers, you mentioned using 10mm pipes. At the same pressure (1 bar), wouldn't 10mm pipes give far less flow in comparison to the standard 15mm pipes? Your system won't be at 1 bar, it'll be more like 0.1bar as it's supplied by the wee F&E tank in the loft = gravity. That's by-the-by, tho', as the flow will be driven by the pump in either system type. Yes, obviously 10mm has more resistance than 15mm, but should be able to handle an average DP rad with no issues. However, I was only suggesting it if you wished to hide the pipes all the way - it would be easier. You certainly don't want any of it on show - it's well ugly and wobbly...

Hiding pipework There is no standard way to hide pipes, just 'solutions'. If, for example, you were to use tall skirting to hide the horizontal pipe runs to the rads, then you could - for example - have the tails coming out horizontally from the front of the skirting, and then elbowing upwards to the rad valves. Nice clearance holes through the skirting to give some 'play', and then fit decor collars around where the pipes come out. That's just an example. Basically, you need to decide how your pipes will run to the rads, and then choose a solution to get them to the valves. If, say, the pipes are clipped close to the wall and you run them at rad valve height, then you could 'simply' elbow them outwards to meet the valves directly - you'd choose a 'corner' type rad valve for this, or else rotate a standard 'angled' valve until they are horizontal. To get a pipe running below the rad 'cranked' out to meet the valve above, you could use 2 of 135o elbows to form a dog-leg.

Radiators I had planned to get Homeline rads by Stelrad. As mentioned in my other thread, they seem to be exclusively sold (and perhaps made) for Wickes. Not sure if this is a bad thing? Not quite sure the best place to get radiators – seems to be mixed opinions. Don't know the 'ultimate' place to get rads, but most are of a decent standard. Kudox from Screwfix, for example. Stelrad too.

Bending pipes vs multiple joints Had forgot to ask this in my initial post. On the run up to the radiator valve, you'll of course have a length of pipe and potentially one or two joints. Method one being: valve > bent pipe > elbow joint > horizontal length of pipe. Method two being: valve > pipe > elbow joint > pipe > elbow joint > horizontal length of pipe. What are everyones thoughts on this? Whichever one looks best in your eyes :-) Also the 'cranked' pipe using elbows mentioned above.

Selling the property Shouldn't be an issue. If it works, it works. However, if it looks too DIY, then it may cause concerns.

Grenage

Soldering isn't difficult as long as you clean and flux everything properly.  The trickiest part is probably not adding too much solder and making it look messy.  A good tip is to bend just enough solder so you know when you have enough in the fitting.

There are always solder ring fittings.

Apodemus

...and make sure you have a good fire extinguisher to hand while soldering!  You'll be using a blow-torch in some pretty tight spaces, very close to the dry, flammable fabric of the house! 

NSG666

Jeepers_Creepers said:

Your system won't be at 1 bar, it'll be more like 0.1bar as it's supplied by the wee F&E tank in the loft = gravity. That's by-the-by, tho', as the flow will be driven by the pump in either system type. Yes, obviously 10mm has more resistance than 15mm, but should be able to handle an average DP rad with no issues. However, I was only suggesting it if you wished to hide the pipes all the way - it would be easier. You certainly don't want any of it on show - it's well ugly and wobbly...

JC I think you've missed the fact that this is a sealed system not open vent. In the first post they talk about filling loop and 1bar

paperclap

Thanks all.

Yes, the central heating system is a sealed system here 

These Tectite copper push-fit fittings do look good. But, do you think they could be used (reliably) across the entire system (that is on show)?

https://www.screwfix.com/p/tectite-sprint-copper-push-fit-equal-coupler-15mm/5808G?tc=LA2&ds_kid=92700055281954514&ds_rl=1249404&gclid=CjwKCAjwgb6IBhAREiwAgMYKRq0UIIAqUjyH8gUvSDwAoUC5nBSKolePQsdXR3fIUz9EhZzxRXxmXxoCQIsQAvD_BwE&gclsrc=aw.ds

travis-powers

My system is 20 years old all done in 10mm pipe and I haven’t noticed any difference!
 Has anyone mentioned fitting a magna clean? Worth every penny.

Jeepers_Creepers

Ah, soz, NSG and LWM - it's sealed. Doesn't make any difference to the water flow rate, tho', as that's purely down to the pump in either system.

Copper push-fits are exactly what they seem - a more attractive version of plastic. And more expensive.

It soldered joints wasn't an option, then - yes - they'd be the ones to use over comp and plastic in any visible section. There is no reason why they shouldn't last for decades as they are designed to. They will almost certainly see you off this planet. (Especially if they leak and flood the house.) (Which they won't.)

But, once you get soldering into your box of skills, you will appreciate it's the 'way to do it'.

Again, you could split the two - use whatever is easier where the pipes are hidden, and then soldered end-feeds for the visible bits. All my under-the-floor plumbing is plastic, and then they change to copper tails to come up to each rad. The copper tails go straight in to plastic elbows.

If I had your task, I'd probably channel the pipes into the wall, and make them 10mm copper. I'd then either remove the old skirting to form a channel behind them (if the skirting was nice enough to reuse) or over-clad them like I suggested if I wanted tall skirtings (which I do). Where the 10mm pipes come down to meet the skirting, I would simply bend the pipes to change direction = fewer joints, and less friction. Then either 10-to-15mm reducers in reverse to get to 15mm copper tails, or just continue in 10mm and cover then with 15mm decor pipe sleeves. This is what I did in our recent extension - two column rads on opposite sides of the room. 15mm tees off the existing F&R, and then 15x10x10 tees as soon as it came into the new room. Builder had laid a solid floor, and this had 4" of rigid insulation over it. I sliced a 'V' into this to half depth, lifted out the V, slightly widened the bottom of the V to take 2 of 10mm plastic pipes, and then poly-glued the V back over it. Nigh-on invisible. The 10mm pipes were flexible enough to loop up at each end up the wall, where I then fitted 15mm elbows, 10-15 reducers, and 15mm copper tails coming straight out the wall. P'boarded over, rads in place, decor collars over. The far rad has a 6m run of 10mm to get to it - makes no difference, it's as hot as the nearest rad - they just get 'balanced'. (Oh gawd - 'balancing' - that's gonna be another bundle of laughs for you later...)

You just need to sit down, look at where the rad will go, and work out how you want to approach this.

I'm not trying to get you on to 10mm pipe - if it doesn't give you an advantage, then don't go '10'. If you are going to surface-run the pipe above the skirtings, then go '15'.

But, if you do go '10', then it shouldn't cause any issues at all provided you keep your system clean = inhibitor.

NSG666

laurencewhymark said:

Thank you so much, everyone!

Boiler / System
Sorry, I hadn't mentioned this in my initial post. We have a conventional boiler. I had planned for the work to take ~3 days to complete from start to finish, and therefore was going to simply "shut off" the entire system, including the hot water. If we need a shower, we can nip to a friend's house!
You say you have no plumbing and soldering experience so I really would recommend that you deal with one drop down leg at a time even if for no other reason than you'll have fewer joints to check for leaks each time you pressure back up - say you are unfortunate and there's a problem with the lounge rad leaking then you look in a bedroom and there's a leak there too. You'll end up running round like a headless chicken trying to catch the water. That's not having a go at you I'm just trying to help you stay in control.

Refilling
That's a good point regarding the inhibitor. Would it be an idea to repressurise the system (without inhibitor) to test for leaks? Then, irrespective of leaks, drain down the system (good chance to test the new drain-off valves, too!), then repressurise with inhibitor when all okay.
Nothing wrong with you doing that but in fairness if you use the method in my previous post you'll have checked every joint prior to the radiator tails and flushed the debris out. If your towel rad is the type with the vent plug pointing vertical then towards the end of the whole job, drain the towel rad and close both valves then remove the plug and pour in the inhibitor. Only open the valves again and bleed when you are happy ther are no leaks elsewhere.

Using PTFE tape
As far as I'm aware, there doesn't seem to be a "go to" number of revolutions for using this stuff. I've watched videos where plumbers have done just four revolutions, and others seem to do 15!
It's down to experience and feel. Too much and with arms like Popeye and you'll damage something. Not enough and it will leak. On the tails for valves with the ground faces I'd often use 20!

Valves
I had planned to get Drayton TRV4 valves. Anyone have experience with these?
I've got them in my house and they are good but expensive but they tend to be on 5 all of the time (main thermostat set at 18.5) and only get used if I need to turn one off to remove a rad. Drayton, Danfoss, Honeywell all good but any of them can seize up or the head fail.

Solder joints vs compression fittings vs push-fit fittings
I hadn't actually given compression fittings any though. That said, they're much bulkier than solder joints, so not too great to look at! Push-fit fittings are quite bulky too, aren't they? I think solder joints look seamless, though granted, they do of course require soldering (the hard part!) Has anyone had experience with copper push-fit fittings? These could very well be the best solution for ease of installation and aesthetics. Tacpot12, noticed you mentioned you had used these a small job. How were they? Any issues?
Don't forget the rad valves have compression fittings hence why I talked about using Hawk White or Tru Blu on the olives. The purists will say you don't need to use it but I do and I've taken apart many a joint where others have too.
I've occasionally use copper push fit but very rarely. For what you are doing I wouldn't advise it and it could make the job look a bit DIY. Also blathering a soldered fitting with paint won't affect it but it might on the push fit if it gets near the o-ring.

Hiding pipework
Any drop down legs will be boxed in (plasterboard and battens). I hadn't planned to hide any horizontal pipework, to be honest. Though, I have seen people using rebated skirting board. To hide 15mm pipework, we would need to get thicker skirting (25mm deep), and have it rebated by 19mm (leaving 6mm material). Additionally, the small length of pipe and elbow fitting running up to the radiator would sit quite awkwardly coming out of the skirting, wouldn't it?
I the same way that you are going to batten and plasterboard the verticals, you could run a couple of battens along the wall (top one the height of the skirting) and fasten the skirting to them but it does make the pipework a bit more fiddly and can be a pain to remove the rad in the future if you don't have enough movement in the pipes to get the valves off.

Radiators
I had planned to get Homeline rads by Stelrad. As mentioned in my other thread, they seem to be exclusively sold (and perhaps made) for Wickes. Not sure if this is a bad thing? Not quite sure the best place to get radiators – seems to be mixed opinions.
Nothing wrong with them. Personally I'd go with the Kudox and get the TRV deal from Screwfix but if you choose to go Stelrad and Drayton that's fine.

Bending pipes vs multiple joints
Had forgot to ask this in my initial post. On the run up to the radiator valve, you'll of course have a length of pipe and potentially one or two joints. Method one being: valve > bent pipe > elbow joint > horizontal length of pipe. Method two being: valve > pipe > elbow joint > pipe > elbow joint > horizontal length of pipe. What are everyones thoughts on this?
Another way I've seen is rad valve, shortest possible length of copper out of valve then elbow to wall, short length of copper then elbow down wall, short length of copper then elbow along wall. This can be useful if you need to keep the pipework compact and if you want to batten the wall to cover the pipes with skirting. Nothing wrong with any of the methods and as JC has said you can create dog leg using 135 degree elbow.

Just picking up on something FreeBear said about the valve tails being rough. Some valve tails deliberately have a series of lines running across the thread (i.e. the direction of water flow) and I believe these are to aid the use of pipe-cord instead of PTFE. These 'cuts' help keep the pipe-cord in place as you fit the tail to the rad. You can use PTFE with them though.

Controversial: I'd just use standard lock-shields and not bother with any drain down as they look ugly but then I'd know what to do if I needed to drain the system or remove a rad with less than an egg-cup of water being spilled.

Grenage

Apodemus said:

...and make sure you have a good fire extinguisher to hand while soldering!  You'll be using a blow-torch in some pretty tight spaces, very close to the dry, flammable fabric of the house! 

Aye, soldering mats are a must-have.

Section62

laurencewhymark said:

Bending pipes vs multiple joints
Had forgot to ask this in my initial post. On the run up to the radiator valve, you'll of course have a length of pipe and potentially one or two joints. Method one being: valve > bent pipe > elbow joint > horizontal length of pipe. Method two being: valve > pipe > elbow joint > pipe > elbow joint > horizontal length of pipe. What are everyones thoughts on this?

In terms of water flow, bending is better than using elbows because it provides a gradual transition from one direction to the other, the pipe bore is also smooth and free of circumferential ridges and troughs which impede flow.  For hidden pipework I'd definitely prefer using bending as much as possible, space permitting.

Having fewer joints also reduces the number of potential points of leakage.

Less clear is the impact on aesthetics. With domestic plumbing what tends to matter is what people expect to see. So in a location where you'd expect to see an elbow, a bend can look out of place.  However, achieving a change in two directions close together using combinations of elbows can look clumsy and is often an obvious indicator of a DIY job.

You'll be living with and looking at the pipework for the next 'x' years, so do it in the way you think looks right.

My view on copper pushfit fittings is they are Ok for occasional use, but in real-life situations look a lot more bulky than the pictures suggest.

Also, it is absolutely vital that you don't try sticking a finger into a joint. The joints are usually non-dismantlable and contain sharp metal 'grippers'. If you insert a finger you'll almost certainly need professional help to safely remove it again.