Downstairs Rads Not Working

The downstairs rads in my house have suddenly stopped working. Upstairs is fine but downstairs are all completely cold including pipes into rads.
The house has 2 thermostats, 1 for upstairs & 1 for downstairs.
Any ideas what could be wrong? do I need a plumber? have been trying to get one for shower jobs for months & no luck!

What kind of heating fo you have? oil/gas ?

We had a same problem where as all upstairs rads were stone cold but downstairs hot. Got plumber and we had a leak. lucky it wasnt a big job and only ripped up two tiles. Is this a new house? If so contact the builders plumber perhaps? Have you checkd the rads to see if they are air locked? sorry im not much help, im in no way a plumber just telling you of my experience!

Blueshoes

It's a gas heating system. I tried bleeding the rads even though they were stone cold incl pipes, no joy.
I'll try ringing around now!

Our's was gas too. What make boiler do you have? How is the boiler like is it going on? Ours was starting and then stopping and the temp was way way up on it. Any funny noises? any ticking noises anywhere in the house?

no it seems to be the same as usual.
Thanks for your help.
I rang the Bord Gaid man who serviced the boiler & he said it sounds like the thermostat for downstairs (because there's separate upstairs & downstairs). I've booked a guy to call out this evening so hopefully he shows up!

turn off all the rads in the house, also turn off the control valve in the hotpress which will be the pipe coming out of the side of the tank.

Start with the furthest rafd away from the hotpress downstairs and turn it on, when it gets hot leave it for 10 minutes and then move onto the next one and so on so on. the last thing to turn on is the control value in the hotpress.

There must be air caught in the pipes that cant reach the rads, by doing this the pressure will force out any air.

This should work if not get a plumber out.

This happened to me before. I can't remember which worked for me, but try turning the thermostat upstairs either (1) a good bit higher or (2) a good bit lower than the one downstairs.

That downstairs thermostat is controlling a motorised valve that feeds the circulating pump . It is possible that the motorised valve is gone faulty & not opening to let the pump send the water around

Its a motorised valve problem, when they malfunction they default to the off position, however there is a manual overide on the valve. Firstly you will have to id the valve, they all look similar and you should find it near the boiler or in the hot press, it looks like a box stuck on the pipe, feel around the box and you'll find a small lever, push this to the side and you will hear the valve opening, as soon as you have done this it may want to automatacally shut again, so when you have the lever pushed to the side lift it slightly because there is a groove the lever sits in to prevent this happening. this will leave the valve on regardless of the theremostat.