Boilermate tank not filling

Hello, hope you can help.
I had a repair made to my boiler and had to have Boliermate/system drained. The engineer said that the tank would take its time to refill and then left heating to come on then I could shut this off. After nearly 5hrs heating did not come on, I have hot water but it sounds as though tank is constantly filling (running water, gurgling sound). No water coming out of overflow but boiler and pumps constantly firing. Radiators are cold. I have had engineer back out and does not know what problem is - can you please suggest any solutions? Thank you.

Which unit?
Mike

Boilermate II. Header tank has been manually filled as block in cold water inlet. Feed to heating system appears to also be blocked. Engineer talked about power flush,£600, but wasn't convinced this would sort the problem.

Can not power flush your unit.
Look through the posts ref BM II.
You could try filling unit / system via drain off on unit or on heating system.
Your area?
Mike

There appears to be at least one blockage comin from the tank that's feeding the radiators. In Glasgow. Engineer back out today so well see what he has to say.
Thanks