Strange: Two Radiators Not Heating

[sarasara]

Hi All,
I recently had my boiler serviced and since then two of the radiators are cold when the central heating is switched on. Both of the radiators have no facility for a bleeding key but both work very well if I have my solid fuel range on. I thought it might be due to the range pump (btw there is also a main pump for the central heating) so I tried it off and on but no luck.

I am totally baffled by this as the copper pipes taking water to the heaters are hot but the radiators cold, the nearest to the system is a tiny bit warm bottom and top. As I said had I lit a fire in the range they would both be hot. The man who serviced the boiler is now overseas and non-contactable, I wanted to ask him if he had changed any settings.

I do find however that in the morning when the heating has been on for three hours to heat the bath the radiators do heat. Hopefully someone might know the answer and thank you for your assistance.

 

[yerino]

Have you tried turning off ALL the other radiators with only your boiler on?

 

[sarasara]

Have you tried turning off ALL the other radiators with only your boiler on?

That I am unable to do. the house is an old stone house which is rented. The landlord sealed the upstairs radiator so that it can never be switched off (not the rad I am having problems with btw). Again this evening I had the radiators on for three hours and after about two and half the cold radiators came on. But this is no good because I only wish to run them for a short time to heat my cats room which is the coldest in the house and three hours makes my part of the house so hot I cant sleep. And is burning cash.

 

[seco services]

tell the landlord to get his ar*e round and sort the heating that your paying rent for.

 

[yerino]

It could be a number of things.

1) Your system might need balancing. (Eg, the rads that come on quickly and get hot need to be turned down and therefore pushing heat quicker to the other rads.. and do this with every radiator till they all come on at the same time.

2) You might have a partial blockage on the pipework going to the cold radiators and therefore taking twice as long to flow/return (heat).

3) The actual lockshield/thermostatic valves on the side of the cold radiators might be faulty (pin stuck, etc) and therefore not allowing the correct flow through, and therefore takes it time to heat up.

.. Try/check those and we'll go from there.

 

[picasso]

As already said get your landlord to sort out your heating, solid fuel systems shouldent be played with if you dont know exactly what your doing.

 

[sarasara]

It could be a number of things.

1) Your system might need balancing. (Eg, the rads that come on quickly and get hot need to be turned down and therefore pushing heat quicker to the other rads.. and do this with every radiator till they all come on at the same time.

2) You might have a partial blockage on the pipework going to the cold radiators and therefore taking twice as long to flow/return (heat).

3) The actual lockshield/thermostatic valves on the side of the cold radiators might be faulty (pin stuck, etc) and therefore not allowing the correct flow through, and therefore takes it time to heat up.

.. Try/check those and we'll go from there.

Thanks Yerino,
Ok, so I ran the test with all rads switched off exceot the one upstairs which appears to be glued with superglue or something and the two radiotors I am having prroblems with. The nearest rad to the boiler heated up hot and fast while the furthest away heated from warm at the top and cold at the bottom to eventually warm. Note that the two problem rads have no bleeding point.

Bear in mind also that all the rads were equally balanced until the man came around to service the boiler a couple of weeks ago. I did complain to him that the water took nearly three hours to heat for the bath in the morning and he did fiddle with the pump and possiby a circulation valve at the back of the boiler.

 

[JohnD]

the "sealed" radiator is doubtless designed to be the heat sink, to absorb heat from the range so that it doesn't overheat.

Solid fuel boilers are slow to cool down, and if the radiators and cylinder were to be turned off when the boiler was full of burning coal, it might boil, if there was nowhere for the heat to go.

As this is a rented house, and solid fuel as well, it is probably not a DIY job, except that if you turn off the hot radiators, the heat wil usually flow to the cold ones. If so, the hot ones can be adjusted down until all radiators are about equal in heat.

Maybe your cat could sleep next to the always-on radiator, or the boiler? In any case, she probably has a fur coat and is not as delicate as she pretends.

 

[sarasara]

Well firstly Verino the rads were all set on full however I did a lowering version of your second test (though it took a long time for the system to cool down from the last, hot day here today). So i started with all the hot rads turned down, this cooled the hot rads and heated the first previously slow functioning rad. The furthest away rad did not come on but prob would have after two and a half hours or so. so really no difference much except to the neares rad. The last rad is warm at top cold at bottom but has no bleeding facility. But with all the rads on full the whole system would be warm in 2 and a half hours, muc too long just to heat a room.

Secondly John D, The sealed radiotor at the top of the stairs was only sealed when I said i might not use it. I think he glued it to ensure (quite righty as it turned out) that that room had to be heated.