Replace radiator on sealed system

[givingitago]

Hi all,

I'm renovating our bathroom and want to replace the old rad with a towel rail. I'm tiling the bathroom, so I know that once the rad is off the wall it's going to be a few days before I can put up the new rail. The family can survive without heating in the height of June(!) but they'll be wanting hot water, so I wanted to check with the pros that my plan is ok.

The CH/water run off a Vokera RS 20-80 Turbo combi boiler, with a sealed CH system. The new towel rail has the same pipe centres as the old rad, wall spacing looks ok so hopefully no pipework mods required. Would the following be a suitable plan of action?

- set CH to summer setting. Filling loop closed.
- open upstairs rad bleed valves, including one to be replaced
- drain system to below level of upstairs rads
- close rad bleed valves
- remove bathroom rad
- cover tail pipes to stop contaminants
- close CH flow and return valves on boiler
- allow family to use boiler for hot water while I tile etc
- fit new towel rail, leaving both rail valves closed
- open an upstairs bleed valve
- open boiler flow and return valves
- start re-filling system from filling loop, waiting for water to run from open rad bleed valve
- close bleed valve, go to next upstairs rad, open bleed etc
- repeat till i get to towel rail
- add inhibitor through towel rail valve then fill it/bleed it
- check pressure on boiler gauge is good
- check filling loop closed
- test CH

I know the boiler is ancient (18 years or so) but it runs well - its next annual service is due in August.

Thanks in advance for your wise words - this forum is great 🙂

David.

 

[SimonG]

So your plan is to drain system for a few days whilst you do the work?

Just take rad off, close radiator valves, drop rad off, do what you need, drain down, fit towel rail, connect up, inhibitor in and refill. Simples!

 

[kay-jay]

op could have had it done in the time taken to write the post lol

 

[Ian10261]

As above, if you stick with your original plan and vent the upstairs rads before you drain down, you or something (probably the carpet) is going to get wet until the system de-pressurises.

 

[PlumbBobBob]

i agree you don't need to drain down until you are ready to fit the new rad unless you don't need to change pipework in which case just fit rad, fill with inhibitor open valves to fill rad and top up via filling loop if needed.

 

[GQuigley67]

I would suggest draining the system and altering pipes to change them to chrome pipework. Looks much better with a towel rad, as it is also chrome.

but do this in the 1 day, then fit the new valves onto pipework and close them and refill system so you can use both heating and hot water then you can tile the wall and fit towel rail when ready(put inhibitor in the top of towel rail then open valves)

 

[Gray0689]

I would suggest draining the system and altering pipes to change them to chrome pipework. Looks much better with a towel rad, as it is also chrome.

but do this in the 1 day, then fit the new valves onto pipework and close them and refill system so you can use both heating and hot water then you can tile the wall and fit towel rail when ready(put inhibitor in the top of towel rail then open valves)

I agree chrome looks far better even chase in to wall and use angled rad valves looks great

 

[GQuigley67]

just gave me a great idea for a tricky one I've got to do next week, thanks lol 🙂

 

[Gray0689]

just gave me a great idea for a tricky one I've got to do next week, thanks lol 🙂

No bother mate

 

[givingitago]

Thanks, guys. That was quick!!!

I should have mentioned I also need to fit the final floor tiles around the tail pipes, and I want to replace the rad valves for the new ones I got with the towel rail, inc thermostatic valve. I want to avoid splitting the floor tiles so I've cut holes in them to drop over the tail pipes, but that means removing the existing rad valves from the tail pipes so the tiles fit over.

Given other stuff going on I was thinking this whole process might take me a day or two, so wanted to make sure it's safe to run the boiler on hot water only in the meantime, with the CH off and the 'open' pipes in the bathroom. I could replace the old rad valves straight after tiling, I guess, but I would still have needed to drain and de-pressurise to avoid, as Ian puts it, getting something wet?

Thanks!

David.

 

[GQuigley67]

also its worth mentioning don't know if you know or not that when your system is drained you CANT use hot water, so you will have to alter the pipework and then fit the valves and close them so you can repressurise the system and follow manufacturers Instructions in bleeding the system also remembering to bleed the pump.

 

[givingitago]

wow so many replies while I typed! I'd love to chase into the wall, but the missus has me on a tight deadline and this is an old house where everything ends up being more complicated than expected, so I don't want to try biting that one off quite yet!! Thanks for the suggestion though 🙂

 

[Gray0689]

If it's a upstairs bathroom drop pressure drain rad take off rad put on some push fit stop ends if copper if chrome use compression stop ends then if you want you can re pressurise heating and use and just do same when you need to tile then put rad valves on and re pressurise again job done

 

[Kimou]

I wouldn't mess about with flow and return valves on boiler. If it's that old, they'll probably leak. Switch off the power to boiler should be your first task before drain down.
Leave rad valves on tails once you removed the rad and no debris will get into the system.
The boiler should still be able to circulate part of the primary system even if you're only using the HW.

 

[givingitago]

Nice one Gray, thanks. It's copper, which I have cleaned and polished to like as nice as I can, tho I agree chrome would be nicer still.

PS am going to be out for next few hours so pls excuse me if i can't reply. I had not expecrted such quick and great responses!

 

[Gray0689]

Nice one Gray, thanks. It's copper, which I have cleaned and polished to like as nice as I can, tho I agree chrome would be nicer still.

PS am going to be out for next few hours so pls excuse me if i can't reply. I had not expecrted such quick and great responses!

Best of luck mate hope all goes well for you

 

[kay-jay]

if you can't change pipework to chrome there is always the plastic chrome snappit pipe covers. not great really but looks a bit better than normal copper pipes on a chrome towel rail.

 

[givingitago]

Thanks, everyone, that's been really helpful. I didn't know I couldn't use the hot water without the CH, so you have probably saved me a lot of pain! I'll crack on with this tomorrow, and maybe get myself some of those snappits!

Thanks again,

David.

 

[givingitago]

Hi again,

Thanks again for the help so far! I started refilling the system after following the above suggestions, and the boiler - a Vokera 20-80 R.S. Turbo (not flowmatic) - started to drip. I stopped filling and took a quick look and it seems it's coming from the auto air release valve, approx one drip every two seconds and gradually slowing. The CH pressure gauge is still at zero.

The black cap/knob on top of the air release valve doesn't seem to want to turn in either direction and there is some limescale around it's base and part of the body of the valve housing, perhaps suggesting it may have leaked in the past (maybe fixed in an annual service? We did have a drip for a while a few years back which i had thought was condensation.) Please see pic below. The top of the valve housing is a little wet, but most of the water seems to be coming from what feels like an opening in the rear side of the valve housing. The opening feels like it's part of the design, as far as my fingertip can tell.

The first step in the instructions for initial filling of the boiler says to open the black cap one turn and leave permanently open, so I assume it's open but scaled up.

Is it normal for water to come from this valve while refilling? I did partially drain the system a few weeks ago, when I thought I would have time to replace the rad etc but in the end didn't, but I didn't get any dripping or leaking that I was aware of when I refilled that time and the hot water and CH have run fine in the meantime.

The process I followed was:
- switched off boiler, extinguished pilot
- dropped the CH system water level to below the bathroom rad tail pipes via downstairs drain point, opening upstairs rad vents to help the process. The bathroom is upstairs, btw.
- closed drain point
- closed upstairs rad vents
- removed old bathroom rad and valves (catching the excess water)
- laid floor tiles around tail pipes
- fitted new rad valves on the the tail pipes and closed them
- opened filling loop on boiler till I could hear water flowing, per instruction book, to start refill
- opened vent on lowest upstairs rad until air stopped escaping - no water came out though
- went to next rad and started to let air out
- closed vent as wife had called out that boiler was now dripping
- closed the filling loop.

Did I mess up? Is this normal or is the valve gone/going? Or..? Hoping you'll be kind enough to help me again -

David.

 

[SimonG]

Put a cloth round it whilst filling up, sometimes you can get a bit of water through an auto air vent. Once its upto pressure it should stop.

 

[GQuigley67]

:iagree:

if it doesnt stop then replace the AAV, might be near the end of its life

 

[givingitago]

Fantastic! Thanks, Simon - phew!!

 

[givingitago]

Thanks GQuigley67 🙂