Question on changing radiator valve

sbsquarepants

Hi Folks,

I have a couple of leaky radiator valves i want to replace, 1 upstairs and 1 downstairs, but i can't see a valve anywhere to drain the system? I would have assumed there had to be one somewhere, but if there is it's well hidden!
Any ideas on how to proceed in the absence of one?

BrokenArrows

sbsquarepants wrote: »

Hi Folks,

I have a couple of leaky radiator valves i want to replace, 1 upstairs and 1 downstairs, but i can't see a valve anywhere to drain the system? I would have assumed there had to be one somewhere, but if there is it's well hidden!
Any ideas on how to proceed in the absence of one?

The drainage value should be placed in the lowest radiator in the house.

If there are none on the radiators then it can be done through the central heating system. You will need to check your heating system as it will be different for all of them.

sbsquarepants

What do you mean through the central heating system?

My plumbing knowledge wouldn't be great! Any other house i've lived in had a valve you could stick a hose on and let the rads empty out the door, but i can't see one in this house.

The valves have been dripping since i moved in and i've been long fingering it for this very reason, but the boiler is now starting to act up, which google tells me may or may not be connected so i want to get them done and rule it out either way.

jmBuildExt

I've done it by closing a radiator valve and drainng the pipe side into a bucket. Was a bit messy at the start...plenty of towels.. Was a while ago... think there was a bit of play on the pipe so i was able to get it away from the rad.
I was only changing a valve upstairs, so only had to empty it to below that.


In my case there was a drainage valve but someone brought the tiles up under it and you couldn't get a hose near it.

stratowide

Plenty of towels,2 pairs of quick hands..job done.:)

Sleepy

I've never been able to locate a draining valve in our system so what I've done a few times in the past was turn off the supply to the system in the hotpress, close both valves on the radiator nearest the back door, drain that rad into basins and then attach a hose to the feed valve for that rad (which conveniently has the same threading as used to connect a hose to an outdoor tap) and open the valve I've attached the hose to which then drains the system out into a shore in the back garden.

Sleeper12

Most older homes don't have a drain off valve.

I would go to the lowest rad in the house & close to a outside door. Close both rad valves. Loosen nut on one side of the rad and get a good quality heavy duty black bag to drain the water into. Open the vent too. When rad is empty connect garden hose to the valve with a bit of pipe in the hose & a nut & ring on the other end. You can now drain the whole heating system if you want. Obviously make sure that the filling valve is turned off. Otherwise it will take a long, long time to drain.

If you do all of this, it's the perfect time to fit a drain off valve to save you from repeating the black bag trick in the future

bonzodog2

You might consider blocking the outlet from the heating header tank with a rubber bung, also the expansion overflow into that tank.

TheBoyConor

stratowide wrote: »

Plenty of towels,2 pairs of quick hands..job done.:)

Exactly. If you are properly set up, have everything to hand and work quickly, you should able to remove the old valve and screw on the new valve with hardly a cupful of water coming out, which will be easily soaked up by plenty towels. I've done it a few times. Easy.

You'd be mad to drain the system unless you really have to because you are making a lot of work for yourself then because you'll have to bleed all the rads a few times.

Water John

If there is an air vent valve near the boiler, this would be oil, turn it 90 degrees and it will leave off the water. That would dump most of it. Tie up the ballcock in the small attic tank first.

In the UK, they have a gadget that clips over the pipe and freezes the water. This allows one to cut even mains pipes. Haven't seen plumbers use them here but they are available.

Sleepy

Oh, make sure to add an inhibitor back into the system if you do go the route of draining the system.

https://www.ie.screwfix.com/sentinel-x100-central-heating-scale-inhibitor-1ltr.html

TBH, based on the colour of the ****e that comes out when you do drain a system, I've often wondered if it's worth draining it down every couple of years as routine maintenance.

Sleeper12

Sleepy wrote: »

Oh, make sure to add an inhibitor back into the system if you do go the route of draining the system.

https://www.ie.screwfix.com/sentinel-x100-central-heating-scale-inhibitor-1ltr.html

TBH, based on the colour of the ****e that comes out when you do drain a system, I've often wondered if it's worth draining it down every couple of years as routine maintenance.

Installing a Magnaclean to the system it should cut out all the gunk in the system & save you money in the long run.



http://www.heatmerchants.ie/page/magnetic-filtration/307

CaptainCoPilot

What sort of boiler have you? Is it oil?

Most oil boilers have a drain off, drain it there if you can.

sbsquarepants

TheBoyConor wrote: »

Exactly. If you are properly set up, have everything to hand and work quickly, you should able to remove the old valve and screw on the new valve with hardly a cupful of water coming out, which will be easily soaked up by plenty towels. I've done it a few times. Easy.

You'd be mad to drain the system unless you really have to because you are making a lot of work for yourself then because you'll have to bleed all the rads a few times.

Really?

I was expecting something more like a firemans hose?

I've twice had my house flooded, so i just don't like taking chances with water. As i said my plumbing knowledge wouldn't be great but i've done the normal diy kinda things like moving a sink, or a dishwasher and so on, but there were always valves to isolate what I was working on so it didn't matter if I took all day....which I usually did!

The floods were unrelated by the way:D

CaptainCoPilot wrote: »

What sort of boiler have you? Is it oil?

Most oil boilers have a drain off, drain it there if you can.

It's gas.

Had a good look yesterday and there is definitely no valve to drain, but also the pipework is buried under the floor screed, the internal walls are solid block. There is very little play on the pipes, just the 100mm or so that protrudes out of the concrete. If i was to damage that i'd be rightly fúcked!

Sleeper12

sbsquarepants wrote:

I was expecting something more like a firemans hose?

It can be. Some heating systems are fed by a small tank in the attic. Not too much pressure and possible to do live if you know what you are doing. Having said that the water will most likely be black and will stain carpet. Bets drain down imp

You may have a pressured system & this will be like a firemans hose. You definitely won't do this live

Sleepy

Sleeper12 wrote: »

Installing a Magnaclean to the system it should cut out all the gunk in the system & save you money in the long run.

http://www.heatmerchants.ie/page/magnetic-filtration/307

I got one put on when we replaced the boiler earlier this year so hopefully that'll keep me from having to do periodic drainings, the inhibitors aren't particularly cheap for what they are!

sbsquarepants

Sleeper12 wrote: »

It can be. Some heating systems are fed by a small tank in the attic. Not too much pressure and possible to do live if you know what you are doing. Having said that the water will most likely be black and will stain carpet. Bets drain down imp

You may have a pressured system & this will be like a firemans hose. You definitely won't do this live

It's not pressurised, but i'm still nervous about taking the chance. I think i'll bite the bullet and call a plumber!

Sharp MZ700

Sleeper12 wrote: »

Installing a Magnaclean to the system it should cut out all the gunk in the system & save you money in the long run.



http://www.heatmerchants.ie/page/magnetic-filtration/307

Got one on a gas boiler replacement, how often should I be cleaning it out?

GreeBo

If you close the other valve on the rad then the re won't be much pressure on the valve you remove, depending on where the rad is in the system there might be considerable pressure on the pipe side of the valve...

GreeBo

I had a drain valve at my hot water cylinder, so church there too.

sbsquarepants

Seems a weird place to put one, would leave the whole dowstairs section full of water?

Sleeper12

sbsquarepants wrote: »

Seems a weird place to put one, would leave the whole dowstairs section full of water?

The drain off on the hot water cylinder is for the hot water in the cylinder. This is for when cylinder needs replacing. It won't drain the heating system though

GreeBo

sbsquarepants wrote: »

Seems a weird place to put one, would leave the whole dowstairs section full of water?

Yeah, confirmation that I shouldnt post when multitasking:D

AlanG

I have replaced around a dozen valves over the years and never drained the system. Close both valves on the rad. Turn of the pressure valve feeding the system and get some help. Disconnect the valve on the rad side (leaving it closed on the pipe) and drain the rad into a basin or pan by opening the bleed valve, have a friend near by with extra pans / buckets. Make sure the new valve is in the closed position and remove the old valve from the pipe. Then quickly stick your friends finger over the pipe. Area should be surrounded with towels. Pop on a new valve and stick it back onto the rad. Open pressure valve near attic and and then open the rad valves until water comes from bleed valve. Close it up and you are sorted. Make sure you have someone with you in case anything goes wrong but you shouldn't spill more than an egg cup of water. make sure you have a cloth between the pipe and the wall also.

Sleeper12

AlanG wrote:

I have replaced around a dozen valves over the years and never drained the system. Close both valves on the rad. Turn of the pressure valve feeding the system and get some help. Disconnect the valve on the rad side (leaving it closed on the pipe) and drain the rad into a basin or pan by opening the bleed valve, have a friend near by with extra pans / buckets. Make sure the new valve is in the closed position and remove the old valve from the pipe. Then quickly stick your friends finger over the pipe. Area should be surrounded with towels. Pop on a new valve and stick it back onto the rad. Open pressure valve near attic and and then open the rad valves until water comes from bleed valve. Close it up and you are sorted. Make sure you have someone with you in case anything goes wrong but you shouldn't spill more than an egg cup of water. make sure you have a cloth between the pipe and the wall also.

Just to add to the above most plumbers will change thousands of valves over the years & despite our training & experience we will almost always drain down the system. It is wonderful reading all the success stories but a real plumber doesn't take chances described above

sbsquarepants

The leak upstairs suddenly got a lot worse, carpet was soaking so i got a plumber in to do it the following morning. For the record he drained the system!

Boiler is still on the fritz though, i'd say it's the original one so would be roughly 20 years old. He says that you can change the circuit board, but it's probably just throwing money away (it had also been replaced already). So i'm thinking a new one is called for.

Does anyone have an idea on a guide price - it's supplying 9 radiators, 3 small ones and 6 larger ones. The boiler is in the utility room, which has no rad in it so i was also thinking of maybe adding a small one in there when it's being done and also replacing all the valves with TRV valves.

Sleepy

If it's that old, you'll probably want to look at upgrading the Heating Controls to avail of the SEAI grant (€700). We had our boiler replaced back in February and had the controls upgraded to zone off the hot water tank from the radiators with a 7 day programmable timer for the hot water and a WiFi enabled thermostat for the radiators. In order to get the grant a new BER survey had to be done after the work was complete but after the grant it came it at €2,300.

Could happily recommend the RGI who did the job for us. I've no association with them other than being a happy customer: https://www.leinstergas.ie/

EDIT: We also got TRVs fitted to all the radiators included in this and the guys actually swapped out a radiator for me at the last minute and included that in the price.

Sleeper12

sbsquarepants wrote:

Does anyone have an idea on a guide price - it's supplying 9 radiators, 3 small ones and 6 larger ones. The boiler is in the utility room, which has no rad in it so i was also thinking of maybe adding a small one in there when it's being done and also replacing all the valves with TRV valves.

Ask this in the plumbing forum. Some great heating guys there can give you a ballpark price

sbsquarepants

Cheers, Will do.