Tiger Loop

23 Dec 2006
Reaction score
United Kingdom
Does anyone know how these things work? My daughters oil fired boiler goes into lockout every morning when it is cold. It has done it for several winters now and as I am staying with her the last few days with no heating I am trying to get to grips with it.

The tank was low so they filled it but no change. The boiler man came and bled the pump saying the tank must have been so low air got in but the tank mans invoice said only half a tank full was supplied.

Anyway it ran all evening but locked out the following morning. I bled the pump again like the man showed me but could not clear the air bubbles. There appeared to be a lot of bubbles entering the tiger loop. The boiler man came back and bled it again and said the problem is that the tiger loop is too low and should be above the pump but I looked on the makers web site and now am not inclined to believe him.

The pump, tiger loop, filters and jets were changed last winter so I am thinking there may be air getting into the system but the tiger loop is supposed to remove it isn't it?

Any ideas?

Sponsored Links
might be wrong but there may be an issue for a check valve some where on the oil line. but in doubt oilman will be there for the rescue :?:
the tiger loop is a de aerator.

tiger loop below pump. correct. in fact ive seen it above...

you may have other issues with cold starts. too much air. incorrect electrode settings

boiler is?and dont say thermecon..........pleease
As wilhelm says, but the first thing to check with persistent lockouts is the value of the motor capacitor. It's no good looking at it, it has to be measured.

Loads of air indicates an air leak, so bleeding is pointless. The leak needs fixing.

Look up Softus Plumbing (google) and give him a ring, or look up his profile and send an email. He's in your neck of the woods.
Sponsored Links
Thanks Guys

They are keeping going by not shutting the boiler down over night. At the next opportunity I might remake all the connections as some of them look a little suspect with lashings of PTFE tape hanging out.

How do I get oil back into the system? Do I need a hand pump or similar to prime the tiger loop and then bleed the oil pump by running it?

just run boiler, itll prob go to lockout a couple of times. or blip boiler stat, beating the lockout, the tiger loop should fill from the pump suction.

theres are other ways . but above is easiest.

DIYnot Local

Staff member

If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.

Select the supplier or trade you require, enter your location to begin your search.

Are you a trade or supplier? You can create your listing free at DIYnot Local