Radiators

[CLCScott]

Hello,
I have a Glow-Warm Back Boiler behind gas fire in chimney breast downstairs. There is a feeder tank in the loft and the hot water is warmed via the coil in the immersion tank. No automatic valves exist. I assume this is what is known as gravity fed.

2 Problems:

1. Had to drain the system to move a rad in one of the upstairs bedrooms, however, after refilling i bled the rads and the rad that was moved only got warm at the top, it used to get hot like all the others before i moved it (i should point out that i fitted a TRV to this rad as it is in a childs room, i have checked the pin and it appears to be free i.e not sticking). After a while it was completely cold, all other rads are hot. Shut off valve is open (or a least i have turned it open all the way, so it should be open as this is also a new valve). I have checked again for airlocks but all would appear to be ok. Booklet for TRV said to fit it on the flow side (picture showed this as the right hand end of the rad so that the arrow could be seen on the valve), i assume this is correct, how do you know which is the flow side?. This rad is at the end of the circuit as far as i can ascertain, it does no appear to tap off.

2. Since refilling i have no hot water (i do if i heat it via the element). The pipe into the top part of the coil is hot, but the one leaving the coil at the bottom is cold. Is this an airlock or a blockage? How do i go about clearing it?

Any help would be much appreciated!!

Many thanks

 

[ollski]

1. the pipe at the end which warms up first is your flow.

2. an airlock....have you bled all the rads and any bleed points in the pipe work (a vertcal pipe at the highest point with a screw cap on)

 

[CLCScott]

1. Thanks, the side with the TRV got hot first so i guess i've got it on the right side. Any ideas as to why the rad is now no longer getting hot?

2. I have bled all the rads and double checked them, there don't appear to be any other valves on the system, not that i can find anyway. What are the chances that sludge etc has got into the coil when refilling the system?

 

[ollski]

There should be at least one bleed point in the pipework to vent out the air collecting at a high point...it may be in the loft, or by the motorised valve or cylinder. It worked for a bit because the air lock hadn't completely restricted the flow....now it has.

 

[ollski]

 

[Antwerpman]

even if the pin on the TRV appears to be free, the valve can still be sticking, try giving it a few (gentle) taps with a light hammer/spanner/wrench and it may release it.

For future reference it is worth checking that these things work before you install them and then you dont have this doubt (easy to say I know!)

 

[ollski]

you have undone the other valve on the rad?....try 1 turn back from fully closed.

 

[ChrisR]

Do a search on "balancing". Try ch with all or most of theother rads closed - should push air through. 10:1 there's an air bleed point on the cylinder primaries (boiler pipes) at the top. If not, crack open the upper joint enough to let air out. (Towels!!)

 

[CLCScott]

Many thanks to those who have replied.

Had success with the rads by "balancing" the system (turn off locking shield valves (i think that's the correct term) and then back open by a quarter, and hey presto the new rad started getting hot.

As for the immersion tank, i followed the pipe up into the loft (as well as feeding into the top of the tank the pipe continues upstairs). It would appear that it bends over into the feeder tank, i assume as some sort of overflow/pressure relief?. Still doesn't appear to be any bleed valves though.

Is the only solution to open the coupler into the coil a bit? The tank is in a very small cupboard and would be extremely difficult to get too.