DIY Central Heating

paperclap

Hi all,

We're renovating our house, and I'm looking to replace the radiators and pipework myself. All the pipework in the loft space will stay as is. I am only looking to replace the "on show" pipework in the living area, as the current pipework is too low for new skirting board. Replacing rads, as they're old single panel ones – new ones will be type 21 rads.

We're in a bungalow, so, no upstairs!

I've literally no prior experience with plumbing or soldering.

Spelling it out step by step, is this correct? Want to make sure I'm not overlooking anything!

Drain down / removal of old rads / removal of old pipework

1. Turn off the boiler
2. Connect hose pipe and jubilee clip to drain-off valve(s)
3. Open up drain-off valve(s)
4. Open up the air vents, starting with highest (for us, the bathroom towel rail)
5. Turn off the radiator valves
6. Loosen radiator valves
7. Remove rads
8. Remove brackets
9. Cut and remove old pipework

New pipework / new radiators

1. Mark up new brackets and radiator, and hang
2. Apply 10 revolutions (with the thread) of PTFE tape to valves
3. Fit the new thermostatic valves / lockshields
4. Mark up talon clips, pipework and any fittings required
5. Fit talon clips
6. Cut pipework to size
7. Deburr pipes
8. Clean outside of pipes / clean inside of fittings
9. Fit portion of pipe coming out of radiator valves / compression fits prior to other pipework
10. Apply flux to outside of pipes (NOT inside of fittings, as could push flux inside pipes)
11. Starting at the bottom of the join, heat join (using propane) as needed, typically about 20-30 seconds per join
12. Use 15mm length of lead-free solder for each join
13. Wait 1 minute or so for the join to cool down, then clean with cloth

Filling the system

1. Add inhibitor into the system via one of the radiators
2. Fit the filling loop
3. Turn on boiler
4. Open up filling loop valves and raise the pressure to 1 bar... and pray nothing leaks!

What do you all think? Have I missed anything?

Thank you in advance.

ChasingtheWelshdream

The experts can comment on the rest, but I'm slowly tackling DIY central heating throughout our house and my biggest tip would be to practice, practice, practice the soldering on spare joints/pipe before you let loose on the real things.

I spent a good week-worth of evenings with Youtube/forums just soldering away, and cut open each joint I made to check how the solder flowed inside before I was happy that I was consistent enough to 'go live'. 

Good luck!

tacpot12

This is quite a big job, with lots of potential to ruin some quite expensive materials (and flood your house) if you get it wrong. Soldering is harder than it looks. You will need a good torch (Rothenberger SuperFire 2 is a good make/model) and a soldering mat. You have forgotten that you will need to balance the radiators after the system is working and not leaking.  

Are you sure you wouldn't be better getting a plumber in to do this? You could offer to drain and remove all the old pipes and rads, and to hang the new radiators, leaving them just to cut and fit the pipes.

If you do go ahead and solder this yourself, I would suggest that you get 20 elbow fittings and 20 tee peice fittings and practice on the elbows and then the tee peices until you can reliably solder them. 

There are some alternatives to soldering. One is to use compression or push-fit fittings. I've used Tectite Pro (psh-fit) fittings for small jobs where the high cost was not a problem. The other is "Copper Seal" or "Just4Copper" which are glues that you can use to join copper pipes together. They are generally suitable for potable water and central heating systems, but you will need to check the specifics. 

Jeepers_Creepers

laurencewhymark said:

Hi all,

We're renovating our house, and I'm looking to replace the radiators and pipework myself. All the pipework in the loft space will stay as is. I am only looking to replace the "on show" pipework in the living area, as the current pipework is too low for new skirting board. Replacing rads, as they're old single panel ones – new ones will be type 21 rads.

We're in a bungalow, so, no upstairs!

I've literally no prior experience with plumbing or soldering.

Spelling it out step by step, is this correct? Want to make sure I'm not overlooking anything!

Drain down / removal of old rads / removal of old pipework

1. Turn off the boiler
2. Connect hose pipe and jubilee clip to drain-off valve(s)
3. Open up drain-off valve(s)
4. Open up the air vents, starting with highest (for us, the bathroom towel rail)
5. Turn off the radiator valves
6. Loosen radiator valves
7. Remove rads
8. Remove brackets
9. Cut and remove old pipework

New pipework / new radiators

1. Mark up new brackets and radiator, and hang
2. Apply 10 revolutions (with the thread) of PTFE tape to valves
3. Fit the new thermostatic valves / lockshields
4. Mark up talon clips, pipework and any fittings required
5. Fit talon clips
6. Cut pipework to size
7. Deburr pipes
8. Clean outside of pipes / clean inside of fittings
9. Fit portion of pipe coming out of radiator valves / compression fits prior to other pipework
10. Apply flux to outside of pipes (NOT inside of fittings, as could push flux inside pipes)
11. Starting at the bottom of the join, heat join (using propane) as needed, typically about 20-30 seconds per join
12. Use 15mm length of lead-free solder for each join
13. Wait 1 minute or so for the join to cool down, then clean with cloth

Filling the system

1. Add inhibitor into the system via one of the radiators
2. Fit the filling loop
3. Turn on boiler
4. Open up filling loop valves and raise the pressure to 1 bar... and pray nothing leaks!

What do you all think? Have I missed anything?

Thank you in advance.

NO! NO! NO! LAWDIE NO!

Ten turns of PTFE is far too much.

I'd also get a pot of Fernox Hawk white - it's an excellent thread joint sealant and lube. Not sure if you use it instead of tape, or as well as!

Everything else is cool.

Very good advice above. Soldering these joints is the 'biggie' in your whole scheme. I presume you want to use end-feed fittings because they are neater and not just because they are cheaper? In which case, fair point.

Watch some YouTube vids on this, unless a plumber comes on here and gives the perfect guide to the process. I've always tended to use Yorkies.

None of this is rocket science, but it does require thinking through and proper planning. 'Fitting a radiator to a wall' is like fitting anything (heavy) to a wall, so that bit is easy. The tricky part is measuring out where the brackets go, getting the correct height for the rad, getting them level, that sort of stuff. For example, a nice tip I read yonks ago was to fit the rad brackets dead level - as you would - and, with the rad in place, sit the level on top, and see if there's a teeny tiny slope. If there is, then fit the bleed screw plug to the highest end.

But the real biggie for you is, how to run the pipes to make it all as neat as possible. All your existing pipework is exposed? And it'll be ditto (tho' boxed in afterwards) for the new? Hmmm, is there anything you can do to improve this?

Can you move the rads closer to the corner where the pipes will come down? Can you replace the skirting boards along that wall so's you can run 10mm pipes behind it? Many moons ago, we had a house with thin, 3" chamfered skirting - which really didn't suit its 'Georgian' pretensions... - so I clad them in 6mm MDF, 150mm-ish high, topped with Ogee architrave - a cheap and easy way to get 8"-high decorative skirting. It also had a 3" x 1/2" void behind it, which would have been ideal for such use.

You can even buy hollow skirting for this purpose.

The good thing about your proposed task is that any leaks will be obvious right away! All the pipes will be in the room concerned, and only the joints in the loft out of sight. You may wish to use compression unions up there rather than solder - with a smear of Hawk White, they are pretty much 100% reliable. Any weep can almost always be sorted with a gentle further tightening. The only thing that can go wrong with compression fittings is that some folk just don't know when to stop tightening - they will crush the pipe until they run out of thread...

Anything else? I would strongly recommend you add a magnetic filter - eg an Adey Mangnaclean - to the return pipe to your boiler. You can then use this to add cleaners, inhibitors and anything else you want (cough - even leak sealer... NO!) If, for example, you find there's a weeping solder joint after you've refilled and run your system, you'll need to drain it all down and will lose any inhibitor. With a filter added, you can fill and run and fully test your system, and - when happy - add inhibitor in 1 minute via this.

That's it! Just give some thought as to how you can make it look as good as it'll undoubtedly work. Position of rads. How to hide pipes.

Section62

Top of the list is to have a plan.  As a novice DIYer it will take you time (days) to do the job, so if the boiler also supplies hot water you need to plan either to isolate the part of the CH you are working on from the boiler, or else have an alternative source of hot water available.  To safely isolate part of a CH system you need to understand how the system works and know exactly what you are doing - so if not, you need to go down the whole system shutdown route.

If you are removing pipes from the system then use some of those to practice on, rather than brand new pipe.  If you can clean up old pipe and make a sound join to it with a new fitting then you are getting good. If you manage to desolder a join and reassemble it using cleaned up parts of old pipe then your soldering skill level is good enough to be expecting to make sound joints every time, rather than hit-and-hope.

Otherwise, clean, clean, clean, and clean again.  Even some traces of oil from a fingerprint can impact on the quality of solder joins, so clean, and then make sure the surface being soldered doesn't touch or get touched by anything other than flux.

Also, make sure that whatever you use to apply flux is clean. If you use a stick or old screwdriver and poke it in a pot of flux then you make the flux dirty. And dirty flux is useless.

On the system refilling part - with the amount of work you are doing (and as a novice) you should really flush the system once you've put it back together. The inhibitor addition ideally should be a later part of the plan.

Not least because when if the system does leak then you'll be draining your brand-new inhibitor away (and buying more), in order to repair the leak(s).

ChasingtheWelshdream

Oh yes, it will take you many, many times longer than getting a plumber in. That's no bad thing, but do allow for it. :-) And ask many questions and be willing to take all advice on board. And quite possibly be prepared to take things apart, re-think and start again if necessary.

I proudly showed off my handiwork on here, and someone pointed out a flaw I had made that I hadn't even thought about. Promptly rectified but I wouldn't have thought about it otherwise.

Don't be put off, but do be realistic. :-)

Another_Level

To be honest its advanced diy in your own property and you can do what you want 

Consider hiding pipes as much as possible, get the correct insurance with legal cover in case there is a serious water leak, fire from using flame tools, falls, personal injuries and many more reasons. 
Dont rely on your insurance company call centre geek to understand and offer false information 

Install everything same as a professional would 

Consider using press-fit fittings, no flame required    Maybe consider nicer looking radiators as an example the stelrad planar (available in many colours) 

Purchase quality fittings, equipment. Try not to buy the cheapest chinese imports, there is a reason why they are cheap  everyone knows why and they are easily recognisable.

Selling the property, dont know where you live but often the vendor needs to fill out protocol forms. Anything more than the well known householder diy plumbing/heating issues needs to be mentioned. So you would need to fess up on all the diy work, not many people do or fail.

Is the boiler under any warranty, any service contract ? 

Not surprised your looking to diy it, decent trades people are busy and are booked up for many month ahead !

NSG666

Just had a thought, if it's a combi-boiler you cannot use it without the heating system being pressurised with at least one radiator connected so you might need to work one pair of drop down legs at a time so that, if necessary, you can use some push fit cap ends on the cut pipes allowing you to re-pressurise the remainder of the system.
If there's a heating water temperature dial on the boiler turn it to minimum and don't turn it back up until you have done.

Use Powerflow flux
you can use leaded solder but at least if you use lead free you'll be able to use it in future on potable water
Contrary to JC, on standard panel rads I use 15 turns of standard PTFE on the radiator tails but on decorative rads I use pipe cord. (Others might disagree but it works for me)
Hawk white is ok for the olives (not the treads) on compression fittings but I used to use Water Hawk as this can be used on potable water as well so it saved me having two tins. That said I started using Tru Blu instead latterly and have recently used it in my own home.

When you come to fill up, turn all of the radiator valves off this way you are testing just the pipework and if there is a leak you don't have any water in the radiators to worry about. On your first attempt you might have got quite a bit of debris e.g. wire wool in your pipework so once you have hung and piped the radiators I'd pop the rads back off so you can let some water run into a bucket through each individual valve. Where the boiler has a mechanical pressure gauge I crank it to just under the red zone to give the pipework a good test. Fit the rads using Tru Blu or similar on the olives. Open the TRV until flow stops, close TRV and open lock-shield valve then bleed the rad - it's useful if you can have someone topping up the boiler pressure as you go. Do each radiator checking for leaks as you go.
Don't forget to put the inhibitor in one of the rads before you test and pressurise it.

FreeBear

Use PTFE tape or sealant on the tails that screw in to the radiators, and no where else. Compression olives do not need any sealant.

When soldering, mix some bicarbonate of soda in to a bowl of water and use it to moisten a cloth. Once the joint has cooled down a bit, use the damp cloth to wipe any flux away. This should stop verdigris appearing and corroding the copper pipe.

paperclap

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!

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.

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

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!

Valves
I had planned to get Drayton TRV4 valves. Anyone have experience with these?

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?

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?

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?

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.

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?

Selling the property
I'm not sure I've ever heard of that, to tell you the truth. I'm sure 90% of British homes have had their fair share of DIY jobs in them, and never had been a requirement to "declare" it as such?

Thank you all again.

FreeBear

laurencewhymark said: I had planned to get Drayton TRV4 valves. Anyone have experience with these?

Use them 'cos they were free with some Kudox radiators from Screwfix - Had a dickens of a job getting one of the tails to seal in the radiator. Ended up having to bin it and using a spare from the odds'n'sods box.

Check the taper threads on the tails, and if they feel a bit rough, reject the box and ask for another.