Radiators not heating up downstairs

[nigelb4873]

Hi there,

I need some help and advice. I took off the two double radiators in the living room in the summer as we decorated the whole room, plus the one in our bedroom as well. I have started the heating up and initially everything was fine as all the radiators seemed to heat up. However, what has happened now is that the radiators downstairs don't come on if the hot water is on but the ones upstairs do, they are nice and hot.
The only time the radiators downstairs come on is when I turn the hot water off, and only one of the pipes going to the radiator is hot, the other end is cold.
When the radiators downstairs do come on they heat up from the top and they take a little while to get hot.
I have bled all the radiators and there is no air in the system at all, I have even tried to bleed the whole system but again there seems to be no air in the system.
I have spoken to my Dad and he seems to think that there may be something wrong with the Tri-Valve next to the pump in the airing cupboard. What do you think?
Also, I have three tanks in the loft, does anyone have any idea what the third tank is for?

Any help and advice would be gratefully appreciated.

 

[pigeon1974]

Hi

Replace the valve or the valve actuator, 3-port valve less than £50.

To test it's working turn the thermostat up and on the hot water cylinder. If it whirrs it's probably ok. If not replace.

Good luck.

 

[bab]

if all the upstairs rads get nice & hot then it may not be the 3 port valve. if you turn all the upstairs rads off do downstairs get hot,(what type & speed is the pump)

 

[nigelb4873]

if all the upstairs rads get nice & hot then it may not be the 3 port valve. if you turn all the upstairs rads off do downstairs get hot,(what type & speed is the pump)

If the I do this and the downstairs get hot, then what could it be? Or if I do this and it stays the same what would it be?

 

[bab]

it could be the pump if it works see what speed its set on , what make is it & how old.

 

[nigelb4873]

it could be the pump if it works see what speed its set on , what make is it & how old.

I don't think it's the pump as I can hear the water rushing through it and both sides are hot. Mind you the pump itself is hot as well. The make of it is GRUNDFOS Selectric UPS 15-50 . I can't tell you how old it is as this was there when we moved in, nor can I tell you what speed it is on as I don't know what it is set on. There is a small plastic dial on what looks like a gearbox and this set in the middle. Thanks for your help

 

[bab]

its a 3 speed pump so it sounds as if its on speed 2 get closer with a torch if u can & try it on three. if the impellers corroded they still sound to be workin but give less flow rate. still sounds like it to me.

 

[nigelb4873]

its a 3 speed pump so it sounds as if its on speed 2 get closer with a torch if u can & try it on three. if the impellers corroded they still sound to be workin but give less flow rate. still sounds like it to me.

Hi Again,

It is actually on 3 so do you think that this will need to be replaced then? The impeller is corroded. What is the price of one of these and where can I get one?

Many Thanks for all your help. Regards Nigel