Air lock in hot water heat system after routine maintenance
I had my boiler cleaned yesterday which according to the receipt included " replaced nozzed, replaced tank filter, cleaned exchanger, cleaned flue pipe, clean and service boiler". My system is a loop with an area of baseboard heat and 5 convector heaters. The water pipe runs around the ceilings of the house. After the serviceman left I realized that the only area still working was the baseboard heat, and the pipes to and from the convectors were ice cold. The serviceman returned and bled the pipes running through the convectors but still no flow. I was told if it didn't correct itself in another 3 days they would return and try to re bleed the system. How could this have occurred with the servicing that was done? Any suggestions to get the air to move. Thanks