priming domestic heat pump

In the middle of a reno, I am at the stage where I need the radiators put back in place. What I have discovered is that I have lost the prime on my pump (Grundfos - circa 1975-80).

Not all of the radiators were removed during the reno and the pump kept the heat in about half of the rads. Then I (not a plumber) decided to drain the water from the system and begin attaching the other rads. Suffice it to say, now there is no heat at all. Boiler still works, domestic water is still hot but not circulating to the rads.

I cannot see any means of repriming the pump easily. On both sides of the pump there are valves I could close.

Please let me know what additional info I could provide as well as any advice on how to get the heat back into the house.

Best regards,
Rowan

Pump

Most so-called pumps on domestic heat systems are not true pumps, they are circulators, what I think is that you have air in your system. You need to bleed all of the radiators, starting at the one nearest the boiler until you have water coming out of all, do not run the circulator pump while you are doing this, [circulators do not like air], once you have done this turn your system back on and see if this helps. Lots of luck.


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" When all else fails, read the directions"

Thanks for the tip, I'm trying it now. How long should it take for the water to fill the pipes and radiators? Also, do I have to bleed all at once or a few at a time? Reason I ask is because about 2/3 of the rads are in place and the last 6 still to be hooked up.

Thanks,
Rowan

rads

If you have radiators they can only be bled one at a time. I assume the uninstalled radiators' openings are all capped off.

granted, I'm a total amature but, why can't i bleed multiple rads at once. Perhaps I already no the answer but the fact is at the moment, I am trying to bleed about 6 on the second floor and 2 on the first. One of the first floor rads has filled and the rest i am waiting for.

Any advice is very appreciated.

Just an update: All day I've been bleeding one or two rads. They do not fill up but every time the boiler switches on, they air pressure starts to hiss out of the valve. Besides that time, it is as though there is no air coming out and I have lost my faith that they are filling up.

problem solved - to some extent. Radiators are now filled but only some of them are warm. It would be nice if all were warm, any thoughts?