Cleaning junk out of a Danfoss oil pump?

[JOEPRO]

Strange one today. My condensing oil boiler (radiators only) wasn't running properly earlier. No heat and it was constantly firing for a few seconds and going again but not tripping out. The motor and pump were also hot to the touch.

First thing I checked was the oil line and a fuel sample. Immediately I could see a load of rust / dirt / junk coming through the oil line.

WTF, I just replaced the oil tank filter with a new one last winter.

Here was the problem. Large bad fitting o ring and metal filter were letting the junk through.




I keep a number of spare parts and that included a paper filter element and new o rings which fit properly.



I fitted that new paper filter and drained another large sample which ran clear this time.

But the oil pump has injested alot of carp here.

Does anyone know is it possible to take the cover off and clean inside these pumps? Or is that a bad idea taking the cover off? Taking all ports off I can't see a mesh filter in there. Maybe the pump is scrap too I guess.



Incidentally this morning I checked FB marketplace and someone 10 mile away was selling a 2 month old identical Elco burner to this and for good £ so I went and got it. Heat running again but the idea is I want to repair and test this one. Then fit 2x new danfoss jets and set both of them myself with my gas analyser and set one aside as a good working spare. 5 mins top to swap the burners out its very easy in these. One electrical plug, one 8mm nut and one fuel line.

 

[julianf]

I've heard of people managing to get them apart and back together, but the risk of my entire oil tank ending up on the boiler room floor is too great for me.

In summertime £60 ish seems to be the going eBay rate for new riello pumps. Iirc the danfos have their ports in different places so I'm not suggesting a swap, but, even at double that, the risk seems grim.


(I had a pump fail like this once - fortunately we were in but it was still a fair "slick" on the floor!)

 

[cheb]

I've taken similar apart and rebuilt them. They're a very simple trochoid pump. Mine needed the drive key replaced, it's a weak point. There's kits on ebay for it.

 

[JOEPRO]

Well it's broken already so I went ahead and looked inside:







Lots of debris in there but I think the pump is AOK, no lasting damage. Simpler pump inside than I imagined which is a good thing.

I will give it a bath in my US cleaner with quality carb cleaner solution to get it thoroughly cleaned and blow the ports all out.

Edit: I see new o rings are available for £5.99 posted on ebay so I'll replace them as a precaution.

 

[Smallfry]

Four years ago, the plastic drive coupling on our Riello burner failed. While replacing this, I took the pump apart as it felt a bit stiff. It was MUCH worse than the one pictured, rust and debris. After a session in the ultrasonic cleaner, I put it all back together , and it is still working fine

 

[Turbo]

I used to service karcher car washes and they used a similar type SP fuel pump. If they are unable to put out enough pressure you can sometimes 'refurbish' them by rubbing the mating surfaces of the gear housing on a flat surface with wet and dry paper until the score marks from the gears goes away.

That method has got me out of a bind several times.

Picture this - a busy service station, fuel pump not working on the car wash. Middle of winter, queue of cars waiting to be washed and the manager not happy.
You've used your last pump earlier, nearest new pump 3 hours away in the stores at base.
Spend 20 mins fixing pump results in a very happy manager and usually a large tip.
Doesn't always work and only temporary, the pump is worn out and will need replaced.

 

[jo1010]

... set both of them myself with my gas analyser ....

Which analyser do you use? I had a look at analysers a while ago and some locked themselves out after a period of time (year?) needing return to base to be recalibrated every year -at a few hundred quid each time ...not too bad if your setting burners every day, but not economic if only used once a year after fitting a new nozzle. Presumably you've got a non-lockout model?

 

[JOEPRO]

Which analyser do you use? I had a look at analysers a while ago and some locked themselves out after a period of time (year?) needing return to base to be recalibrated every year -at a few hundred quid each time ...not too bad if your setting burners every day, but not economic if only used once a year after fitting a new nozzle. Presumably you've got a non-lockout model?

I have s TPI 709r which I hope is still working, was working fine the last time I used it and I don't think it will time or lock out unless it detects a fault.

 

[waddycall]

I used to be a boiler service engineer. I wouldn’t trust an analyser that’s out of calibration. I have seen how wrong they can be. The Fyrite chemical analysers are better long term. That’s what people used before electronic analysers. Oh and don’t forget the smoke pump. An analyser won’t tell you if it’s sooting. They can read low on CO but still be smoking.

 

[Turbo]

I used to be a boiler service engineer. I wouldn’t trust an analyser that’s out of calibration. I have seen how wrong they can be. The Fyrite chemical analysers are better long term. That’s what people used before electronic analysers. Oh and don’t forget the smoke pump. An analyser won’t tell you if it’s sooting. They can read low on CO but still be smoking.

I used to set the karcher boilers using my senses, eyes, ears and nose. Only time an analyser was used was at locations where it was required by the customers insurance such as gov't buildings.
Very rarely did it need any adjustment to pass the test.