Dry tiger loop

[R3su]

Hi all

I’ve had a number off issues with my heatslave 12/18, most recently returning from holiday to find it on lockout with a totally dry tiger loop.

I managed to get it working again by priming the pump via a temporary gravity fed supply. It was then able to draw through oil from the tank.

That’s lasted a week of intermittent hot water use and no heating use. However, this morning I have found the tiger loop completely dry and the pump unable to draw through.

The pump is only a month to 6 weeks old so it is likely just to be air getting in allowing fuel to drain down back into the tank?

 

[oilhead]

Check all filters and joints from the tank forward. you really need a vacuum gauge to test the pump. If the pump was changed, i'd be inclined to recheck the connections into the flexi. What burner do you have and is it low mounted firing forward or top mounted firing down?

 

[R3su]

Hi Oilhead
Thanks for the response. I’ve attached a photo which hopefully should answer your questions (excuse the mess). I believe the burner is top mounted, facing down.

Working from the tank everything is clear, filters fine. I can pull plenty of oil through with a wetvac (I don’t have a syringe) to the ‘fuel in’ at the loop. And can also pull it through right to the pump flexi.

I’ll need to re-prime the pump again by disconnecting the fuel in from the loop and I’ll take the opportunity to nip everything back up again.

 

[Exedon]

You really should have a all metal tiger loop with a 10mm vent to outside, the type you have is for external use.
Was the pump correctly converted to 2 pipe when fitted?

 

[oilhead]

As Exedon says above about the unit, and also worth checking the pump bypass is correct. If you use your wet vac on the feed flexi, does the loop fill up?

 

[R3su]

Thanks both.
With regards to the loop should it be like the old one on the wall? I have noticed it smells a lot more of kero since these works were done.
It’s an out building so I haven’t really worried about it.

When I use the wet vac it just pulls it straight through. The loop stays empty. I figured it wouldn’t have enough flow to fill the loop as well.

We / the engineer did have Issues with the pump when he replaced it (annoyingly when I stripped the old on later out of curiosity I think it just needed a new filter). I’ll have to take a look at the weekend and upload some pictures.

I’m losing confidence in my engineer so will be trying to DIY it until I can find another one.
I’ve also spent a fair bit getting the boiler to its current state and can’t really afford anything else on it this year.

 

[Johntheo5]

I know this might seem obvious but assuming the oil level just now is above the pump suction, if you break this pipe, is there a good flow of oil? a 36kw boiler requires a flow of ~ 4 litres/hr or 67 ml/minute.

 

[R3su]

Hi John
Do you mean the fuel feed after the loop? Between the pump and the loop?

 

[Johntheo5]

Have only seen one TL , in passing.
So I (should) mean the supply from the tank where it enters the TL and from the TL out to the pump?.

 

[Exedon]

If the supply line is clear and the tiger loop and pump is configured correctly you should at most have to reset burner couple of time they often work first time on short oil lines.
As I said before wrong tiger loop regulations now ask for a all metal one vented externally.
Carefully check oil lines between pump and tiger loop are not crossed, and as I said before pump needs to be in 2 pipe mode (out of box they are one pipe)
Should also add without access to at least a pressure gauge and combustion analysis equipment you cannot make any meaningful changes to burner this incudes fitting oil pump.

 

[Johntheo5]

Hi all

I’ve had a number off issues with my heatslave 12/18, most recently returning from holiday to find it on lockout with a totally dry tiger loop.

I managed to get it working again by priming the pump via a temporary gravity fed supply. It was then able to draw through oil from the tank.

That’s lasted a week of intermittent hot water use and no heating use. However, this morning I have found the tiger loop completely dry and the pump unable to draw through.

The pump is only a month to 6 weeks old so it is likely just to be air getting in allowing fuel to drain down back into the tank?

When you get it firing again via the tank. is there a level showing in the glass bowl (if not all metal), up to the time the burner stops firing?, I know the pump pipes below should be going downwards with the tiger loop mounted where you show it, if the non return valve is holding, then, and assuming the two solid copper pipes or theier unions arn't leaking, shouldn't a oil level stay showing in the bowl no matter how long the boiler is shut down. If little or no visible oil level when firing then a indication of air ingress?.

 

[muggles]

Hi Oilhead
Thanks for the response. I’ve attached a photo which hopefully should answer your questions (excuse the mess). I believe the burner is top mounted, facing down.

Working from the tank everything is clear, filters fine. I can pull plenty of oil through with a wetvac (I don’t have a syringe) to the ‘fuel in’ at the loop. And can also pull it through right to the pump flexi.

I’ll need to re-prime the pump again by disconnecting the fuel in from the loop and I’ll take the opportunity to nip everything back up again.

View attachment 278426

Worth noting that this type of oil deaerator has never been approved for fitting internally, it was designed for external use only. Also, the regulations now say that all deaerators must now be made of entirely non-combustible material regardless of installation location, so this is non-compliant in any case. It's been this way for a couple of years.

 

[Servotech]

I'm a retired plumber therefore no longer qualified to do this work, however, looking at that picture the height of the new tiger loop in relation to the old one worries me.
I would lower it down to at least the level of the old one and if possible, drop it down to floor level beside the boiler.
Getting gravity on your side would do it no harm.
Good luck,
servotech,

 

[Johntheo5]

This may be of interest but presume the TL can't prime the system in all cases where the tank is run dry and then refilled.

 

[R3su]

Thank you everyone for your responses! A lot to read up on.

I think I’m going to buy a few lengths of 10mm copper and replace everything from the tank to the flexi. If nothing else, it’ll be a neater job.

Very interesting to read about the positioning of the TL outside and the height in relation to the pump. I can’t say I was very happy about the replacement TL and the butchering of the pipe work to get the new one in.