Running recirc pump in reverse to clear airlock

Vertical · 27-10-2011 9:41pm #1

I have an airlock upstream of a ufh circuit. I've worked out that I should be able to clear it by running the circuit's pump in reverse for a short time.

It's a Heat Merchants own-brand pump. Will this work or will it damage the pump?

heinbloed · 27-10-2011 9:45pm

That's a strange pump, I haven't come across the like.
What type of pump is it ? 230 Volts ?

DGOBS · 27-10-2011 9:49pm

Assume you mean your gonna turn the pump body around to do this

Vertical · 27-10-2011 9:51pm

Yes, 230v. Looks similar to other brands, grey in colour. Installed <2 years ago

DGOBS · 27-10-2011 9:54pm

How do you plan to run it in reverse?

Vertical · 27-10-2011 9:54pm

Was thinking of reversing the phase. I didn't know if the pump would physically pump like this or if it would cause an electrical problem; hence the post.

heinbloed · 27-10-2011 9:57pm

Answering DGOB's question: are you planning to take the pump out and put it in reverse?

For a sludge removal in UFH creating a suction force would be of little help, once the sludge is stucked it is stucked and well compacted. Like clay in a pond's outlet. If the pipe blocked it needs pressure to blow out the plug.

Have you tried to separate flow and return of this particular circuit from the group and just pump fresh water through ? From the pressurised cold DW mains?

PS
The 'reverse' question just explained..... No. That is impossible. This pump is (very likely) not designed to work in a reverse mode.

What type of pump is it?

DGOBS · 27-10-2011 9:57pm

It's a single phase pump so how are you going to reverse it?
Just swapping live and neutral wont work, it would still run in the same direction, and it's the body of the pump behind the impellor that creates the flow direction, you would have to turn the entire pump body the other way for what you want

Vertical · 27-10-2011 10:03pm

Ah...
Sounds like this job requires spanner rather than screwdriver. Was hoping to keep my hands dry!

Thanks for the help

heinbloed · 27-10-2011 10:11pm

You're welcome.

With a bit of garden hose on both ends of the blocked circuit you should get away with a dry floor at least (smiley).

JohnnieK · 28-10-2011 10:16pm

Do you know what circuit has the air lock in it? If you do you can shut everything down leave the problem circuit open. Attach one hose to a garden tap and connect it to the flow manifold. Attach the other hose to the drain on the return manifold. Turn on the tap. open the drain on the flow manifold and open the drain on the return manifold. Leave it run for a while and this should remove any air lock in the circuit.

Running recirc pump in reverse to clear airlock

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