Rad Wrecking my Head

DaveR1

Upstairs radiator, stone cold, will bleed no problem with constant flow of cold water....

All other rads work fine. Have turned off whole system and have left only this rad on in hope increased pressure would solve issue. Nothing.... Have bled while system still warm. Constant flow of cold water. How is cold water still coming out, where is it coming from?

Any ideas / suggestions on either problem or solution most welcome.

Thanks

standardg60

First stupid question OP, is it turned on?

Is the feed pipe warm?

mikewest

How long have you bled it for? You may need to bleed it for a long long time with the system on to clear an airlock and it may be on the supply or return or both.

Close the valve one side of the rad and bleed for as long as it takes until you get hot water coming into the rad. Open that valve and see if the rad warms up, if not, close the other valve and repeat.

standardg60

https://www.boards.ie/discussion/comment/119846685#Comment_119846685

Yep that was the next step, airlock on the system could take a while to clear

Markus Antonius

I also have an off topic stupid question. Does the water for the radiators come straight from the mains water or does the boiler have some kind of resevoir? Does it just top itself up when the water level is low?

DaveR1

https://www.boards.ie/discussion/comment/119846685#Comment_119846685

Will try this next. To continue on from above question, will the system just top itself up replace the lost water? Don't want to end up draining the system!

zg3409

There is a tap at both sides of each radiator. One side is for off/on adjustment, the other side is for balancing the radiators. The other end might be turned off or nearly off and blocked by debris such as mud or rust.

If opening the other end tap, count the number of turns so you can put it back where it's on.

Ideally all radiators should be balanced so if all are on then all give out equal heat. The inlet temperature and outlet temperature would ideally be the same for every radiator, example boiler puts out 60 degrees hot water and each radiator returns 50 degree cooled water.

If radiator is in attic conversion it may be hard to balance the system, particularly if it is an open system with a special water tank for the heating.

Sometimes your water pump (for heating water circulation) may have multiple speeds such as i/ii/iii and 3 is fastest.

Sometimes the valve on the radiator can break, typically it's the single turn trv type with green, blue red temperature settings but typically they break full on. If you have that type (mostly plastic) you can unscrew it and press the pin sticking up a few times which can help unblock the valve if it's stuck with mud or rust etc.

Maybe take some photos of radiator valves, boiler pump etc. and put up here

Akrasia

https://www.boards.ie/discussion/comment/119847011#Comment_119847011

There's usually a valve you can open to manually add water to the heating system. If you're bleeding a lot of water out of the radiators you'll need to add water until the system pressure is in the green zone for your boiler.

It's likely in your hotpress, could be a lever or gate valve (a screw valve) there's often a pressure gauge on the pipe so shouldn't be too hard to find

astrofool

https://www.boards.ie/discussion/comment/119846944#Comment_119846944

Radiators are usually (at least in Ireland) on their own loop with a non return valve (and manual valves) to refill them from the attic supply. If the pressure drops too much, the system won't perform that well and the filling valve should be opened and then closed when back at pressure.

There is usually additives to the water in this loop to prevent rusting (called inhibitor), this is not safe for ingestion, hence keeping the filling valve closed when it's not needed (I think by regs it should be physically disconnected). The non-return valves and manual valves can fail and let unsafe water back into the hot/cold water system.