pesky wallstar & danfoss problems!!!

2 Jan 2012
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United Kingdom
Hello all,

I posted a year ago with problems..... and find myself here again asking/grovelling for your help!

From what I can deduce, Initially (after bleeding/lockout a couple of times), There is a good constant supply of oil to the pump. The boiler fires up, after 20-30 seconds the burner starts to sound like its struggling. It then cuts out, attempts to draw more oil up the line, fails to do so & then goes to lockout.

I have started it up once or twice, leaving the bleed screw slightly open, (even after it fires up), and have noticed that after the initial constant stream of oil, air seems to be introduced from somewhere; the longer this goes on (about a minute or so), the more air replaces the oil, until no oil comes through and the burner cuts out.

I've had an engineer out, who reduced it from a 2 pipe system (with tiger loop), to a 1 pipe system. Both the engineer & hrm wallstar manual say the pump/boiler should be man enough to pull the oil up from the tank (about 1.5/1.6m).

Could the pump still be set up as 2 pipe system? Is the pump knackered after all the priming/bleeding attempts? possible solenoid issues?

Any help with this would be much appreciated, as the missus is chewing my ears off, and I've already forked out for an engineer who was baffled.
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Could be pump problems. Ask your engineer to test it with his vacuum gauge. Also check the non return valve on the oil line if using a sigle pipe system. When it was reconverted to single pipe, was the pump set up properly?
It sounds like air is being sucked into the fuel line at a poor joint? are the oil filters clean? ;)
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Do my posts re Wallstar cutouts ring any bells? Mine is an external wall mounted boiler that cuts out in windy conditions. Has done for years

Look up thread Wallstar cutout - can wind cause it?

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