Downstairs heating and hot water not working - blockage or big air locks?

[Rad1o]

Yesterday evening I put the heating on and it should have been running with the hot water, but downstairs was not getting warm at all and the temperature in the hot water cylinder was not rising. Upstairs the radiators were getting warm. Initially I thought that the pump had failed, but this morning the same happened again. Warm radiators upstairs, but only cold radiators downstairs and still no hot water.
I bled all the radiators.
Our boiler is in the garage and pipes go up into the ceiling, tee off to downstairs and into the upstairs radiators and hot water cylinder upstairs. Pipes were warm this morning. Hot water tees off from a mid-position valve by the boiler.
Last night I thought the pump had failed..... not sure now.
The last time, the downstairs radiators worked, was yesterday morning.

 

[terryplumb]

Pump would be first thing to check out . Is it spinning ?

 

[Rad1o]

I am sure it is and we had half the house heated. Last night I thought it was hot from a burnt motor, now I think it was the hot water.

 

[Hugh Jaleak]

Pump can get red hot, doesn't mean it's actually moving any water. Check pipework coming away from the boiler, how far is the heat travelling?

Upstairs rads may get some heat from gravity circulation, no heat downstairs or hot water would indicate a circulation issue. Also, is there sufficient water in the system, and/or do you have an air separator fitted anywhere on the system? (Tin can shaped device with 3 or 4 pipes coming from it.)

 

[JohnD]

I am sure it is and we had half the house heated. Last night I thought it was hot from a burnt motor, now I think it was the hot water.

If the pump is hotter than the pipes, it is not circulating water.

 

[Rad1o]

The pump is exchanged for a UPS3 15-60/65 and now everything is up and running.
The old one was not coming out easily though.

Does anyone know from the label Model and No what year it would have been. It was in the house when we moved in.
The Model is A and the No is D817.