Hot water but no heating

[TheMadProf]

Hi there

We've just moved into our "new" house which is fitted with a rather old Worcester 400 Highflow standing boiler.

The hot water functions fine. We tested the heating by changing the room thermostat (Honeywell T6360) and the boiler fired up. However none of the radiators get warm.

Is this a boiler problem or a radiator problem? Are there any obvious/cheap/DIY solutions I should try before calling out a professional.

The boiler was also pretty noisy.

 

[JohnD]

when you bleed the highest radiator in the house, does water squirt out forcefully and without dying away?

When the boiler fired up, how long did it continue flaming before it cut out?

 

[TheMadProf]

Haven't bled any radiators yet. Didn't know which ones if any to do. Will check that.

The boiler ran continuously as though heating the water but the radiators didn't get hot.

 

[JohnD]

have you got a hot water cylinder?

Does it get hotter when you try to turn the heating on?

 

[TheMadProf]

No hot water cylinder. The boiler fires when the thermostat is changed but nothing gets warm.

 

[endecotp]

Do you have thermostatic radiator valves?

 

[JohnD]

The boiler fires ... nothing gets warm.

Something must be getting warm. If the boiler is firing and burning gas, it is making heat. If the heat isn't going anywhere, the boiler will overheat and shut down. You said it didn't. So heat must be travelling up pipes and going somewhere. Feel the pipes.

 

[TheMadProf]

Yes, thermostatic radiator valves. Will check piping then.

 

[endecotp]

Are the thermostatic valves open? Set them to max.

 

[TheMadProf]

Yes TRV open and set to max.

 

[Daniel curry]

Probably airlocked. Or worse still airlocked with an auto by pass on the system. Turn all rads off except one and see if that heats up.

Make sure system is filled and pressurised. And maybe u boiler is firing for pre heat hit water. I think they have a dhw store on them fs combis