How hard is it change a radiator yourself?

[User181019]

So I've been trying to get our ancient and ugly radiators replaced for ages. They work but they are just ugly and have been in place for years. I'd like to replace two medium ones in the hallway, one very small one on the stair landing and one bigger one in the hallway. I'll replace with the same size and make sure the pipes stay in the same place. No floorboards to prise etc. We are in London. I don't know what the labour cost would be as we are being ghosted by plumbers who don't return with a quote! Not even the guy we've used a couple of times now for other jobs and recommended to others. The last one seemed interested. Asking me to WhatsApp pics of all the rads to be replaced. Read the messages then just stopped responding :(

Since the pandemic, where we are trades people are doing a roaring trade. We've found it really hard to get good people in to do "smaller" jobs. E.g. tiling the hearths, replacing broken fences. Jobs too time consuming for us : both work full time with kids - and DH never gets round to doing stuff so paying someone saves a lot of arguments and gets things done. I assumed replacing radiators would be at least half a day's work but I'm thinking now maybe it's too small a job compared to much bigger jobs out there.

I've seen guides on B&Q suggesting it's easy to swap out rads for new ones. Is it really that straightforward? Or how much did you pay for labour only and whereabouts are you?

This is a very good post ….. just drain the system first and you wont flood the place 🙂. Also dont get any of the black water on your carpets 🙀 id suggest pulling the carpet up around the radiator before you start.

My very recent experience is that it's not the hardest thing in the world but it's a LOT harder than cheery, sped-up and edited, DIY videos "for beginners" on YouTube make it look. (My pet peeve of late.)

My tips would be:

1. Don't do it at a time of year when you need your heating. Do it when you can drain the system down fully and take your time over it - so spring/summer.
2. From my perspective as a beginner I don't recommend doing it without fully draining the system. A tradesperson can do this in their sleep. But if you don't know what you're doing you'll end up with water everywhere. (And old central heating water is filthy - black/brown and smells rancid.)
3. Radiators are heavier than you think, even without water in them. Small ones are fine but if you have large ones, you'll need two people to lift them.
4. Don't re-use old valves and tails etc. It's a recipe for leaks in my experience.
5. Check measurements (including valves and tails) before you buy to make sure the new rad will fit the old pipe positions. There's some room for manoeuvre (longer tails) if the new one is narrower, but if it's too wide, you're out of luck.
6. Hopefully you can re-use the old brackets and/or the new brackets have holes in the same positions. If not, make sure you use appropriate wall fixings for the new ones.
7. Fill the rad with water (valves closed of course) to check for leaks before you fill the whole system back up with water. You can dab the corner of a piece of toilet paper around the various joints to make sure they stay dry and aren't weeping water.
8. When you refill the system do it in stages to make sure there aren't any leaks. Don't forget to bleed the rads and add some inhibitor.

If you don't want 100 litres of pressurised water to squirt out and hit the ceiling with a closed loop pressurised system, simply bleed one of the radiators to drop the pressure in the system to zero before you start. It's not so hard. You won't have to take much water out if the system is fully filled as water is incompressable. Boilers normally have a dial on them that will show you when the pressure has dropped. Of course you don't want the boiler firing up when you have done this (although most have an interlock stopping them working if the pressure falls below a certain point, normally about 0.5 bar).

I would always lower the pressure down to at least the minimum anyway before starting any work because it is trivial to do (the same as bleeding), simple to replace the small quanitity of water removed if you know how to refill and will just lower the amount of water spraying about if things go wrong. Belt and braces stuff.