SIP Diesel heater inop

[JOEPRO]

I brought this home today. Got it for a song as its not working. Spins but doesn't fire up and cuts off then.

I have tinkered with boilers before with success. First thing I'll do here is order a new nozzle incase that is dirty or worn out since it is a 2010 heater.

Any other idears please?

 

[waddycall]

1) has it got a spark.
2) does fuel come out of the nozzle (You can strip and clean those nozzles in a pinch - the filter unscrew and with an Allen key you can take the guts out)
3) if no fuel comes out check the solenoid coil (hold a screwdriver over it and see if it magnetizes when it’s trying to fire)

 

[Redsailor]

Is there an ignition spark from the two electrodes? Does fuel spray from the nozzle when ignition sequence starts? These steps will narrow the fault down.

 

[JOEPRO]

1) has it got a spark.
2) does fuel come out of the nozzle (You can strip and clean those nozzles in a pinch - the filter unscrew and with an Allen key you can take the guts out)
3) if no fuel comes out check the solenoid coil (hold a screwdriver over it and see if it magnetizes when it’s trying to fire)

Is there an ignition spark from the two electrodes? Does fuel spray from the nozzle when ignition sequence starts? These steps will narrow the fault down.

Thanks for replies.

What I do notice is I was wrong about the year. It seems to be a 2019 model and it has a more advanced fuel system than these normally have. (No air syphon system but ECU and Danfoss pump)



I took apart the ECU and all looks really clean and good. Except I seen what looked like 3x small dry solder joints so I re flowed them.



It starts, turns and very healthy sparking. But cuts out again and no signs of fuel or flame at all.

I did clean the sparkers and ignition light sensor.



I have connected fuel hose straight into known good diesel jar.

It does not seem to be spraying fuel at all. Maybe its got a bad airlock I will look up how to bleed this pump.

 

[JOEPRO]

I fitted a new Danfoss coil I had on the shelf and no difference

 

[waddycall]

Might be worth undoing the grub screws on the end of the motor, pulling the pump off and checking that the pump drive coupling is ok. pump might have seized and stripped the coupling. The pumps are quite simple to take apart.

 

[JOEPRO]

I did take the fuel pump out and all seemed OK.

What I did notice is the rubber fuel hose felt a bit loose at the end. So I added a hose clamp. (May have been sucking in air I thought)

And away it went running really nice plenty of heat in my garage garden and runs very clean even considering it's on diesel there but will be back on its on Kerosene tank next.

I will add a new external in line fuel filter too now.

(These are the latest erp compliant clean burning heaters)



That's a result there I paid £70 for it including a tank of fresh Kero it came with Its about a £500 heater new.

 

[waddycall]

Not bad for just needing a hose clip

 

[JOEPRO]

It worked perfect from the Jerry can. Did a few cold starts all excellent no issues.

Then I connected the hose back onto its own fuel tank barb and ever since it has not fired once. I put an endoscope into the tank and can see the pickup tube is well submerged in Kerosene.

So it has to be one of 2x things. Water in the tank or bad Kerosene.

I guess I will pull a sample into a clear paint pot tomorrow and check if a water layer forms in the bottom. If I can't see any water in fuel samples pulled from the base of the steel tank then I guess the Kerosene in it must somehow be bad. The guy said he put fresh oil in it but you know what people are like too that could have been a fib. Could be 3 year old fuel for all I know. Thing is, does Kerosene go bad like that?

 

[m_c]

Have you checked the pickup tube isn't blocked?

I've had a couple similar heaters apart, and there's been a gauze in the pickup.

 

[JOEPRO]

Have you checked the pickup tube isn't blocked?

I've had a couple similar heaters apart, and there's been a gauze in the pickup.

Good point I can try putting a large syringe on the rubber hose and draw fuel out of the tank barb and see.

I also just discovered this stuff existed and ordered a tube. Will be handy for my house oil tank, lawnmower etc too. Rub some on a stick and dip tank to bottom. If any water is present it will change colour at that area.

 

[JOEPRO]

If there is water in the Kerosene I know it will need drained and disposed of at local recycling centre's waste oil tank.

But how to get the water droplets out? I would presume a certain amount will remain in there after draining. The full cap is also very small and badly located. Even for refueling going to need a bendy funnel just to reach it.

 

[JOEPRO]

OK so I found the last problem and it's all working perfect now off its own fuel tank.

I know what happened to it now. The PO has replaced the rubber fuel line and pickup tube and made several mistakes along the way before giving up. Poor execution really was the problem.

Pickup tube is now copper which is fine except there was a large burr at the end retricting fuel flow. All fuel fittings were only hand tight. And the rubber hose had no hose clamps. All this combined had to be fixed before it would run correctly off its own tank.

Fuel sample drawn from pickup was fine.



It ran OK off it too



Which told me this was a pickup tube problem.

Pickup is copper DIY with large burr which I carefully removed and cleaned.



Thats it now running very nice and on its own tank / fuel which didn't have to be disposed of it was / is AOK.

 

[JOEPRO]

All that is left is the following and it's ready for winter service:

Fit new much longer power cord. It's about 1m long which needs an extension lead so I'll put a new rubber 4m cable on it.

Add an in line clear fuel filter cartridge externally.

Fit a new danfoss nozzle which I ordered already based on the exact spec on the original. Those nozzles are a service item so it makes sense to fit a new one now and bleed for one last time.

For anyone wondering to bleed this there are no other ports. Just slack the high pressure nozzle fitting at pump end for a few seconds when the pump is energized by coil. It pulls the fuel up the line instantly then. Otherwise it will not be happy and may not even start at all after several tries with an airlock.

 

[carbon]

Some of these fuel pumps have a very small fuel filter fitted underneath the fitting marked

 

[JOEPRO]

Some of these fuel pumps have a very small fuel filter fitted underneath the fitting marked

View attachment 422289

I checked in there and behind all accessible blank plugs with the pump removed and there is no filter. I'm sure these were fitted with an external filter from factory. When the PO replaced the fuel hose he must have done away with filter too.

 

[carbon]

The filter blank usually has a little pin on it to locate the filter but I have seen these pumps without filters in them as well but have assumed the users have removed them as they are so small and block easily

 

[Turbo]

Dome of those danfoss pumps had a large cylindrical filter inside the pump body. Remove the 4 cap screws & look inside it.

 

[carbon]

Dome of those danfoss pumps had a large cylindrical filter inside the pump body.

Incorrect, the BFA fuel pumps have a ridiculous small filter behind a screw on the side.

 

[Turbo]

Incorrect, the BFA fuel pumps have a ridiculous small filter behind a screw on the side.
View attachment 422660

If I remember correctly the ones fitted to some pressure washers (KEW??) had a large filter inside the pump. Or it could have been on suntech pumps, it's a few years since I've worked on one!