Riello Pump Seizing Repeatedly

AirborneTrav

Hi guys,
I am having a strange problem with a Riello Burner. This is an F5 on a Viessmann VR1-40. About two and a half months ago, the customer called in the middle of the night saying they had no hot water. We went there, found the pump seized, and changed it out. About a week later, this happened again. At that time, we figured we had just received a bad replacement pump, chalked it up to bad luck, and replaced it. Two weeks later it happened again. At this point we realized we had a problem. We started asking around to see if anyone else had experienced anything like this, both with Riello and other manufacturers, and heard nothing out of the ordinary. We spoke with Riello, and they also said they hadn't seen anything like we were describing. This was about 6 weeks ago. Sure enough, last night at 8 PM I received a call saying it had happened again. Has anyone out there experienced what I'm seeing here? I don't think there is any way it's a bad run of pumps, as the original one was 7 years old. Obviously bad oil is a possibility, but we also take care of this guys office 3 miles from his house, where he has a Riello and uses the same fuel company and has no issues whatsoever. We are located in Suffolk County, NY.
Here are the particulars of the system:
Two pipe system with twinned together tanks about 40 feet away in the basement. Top feed, overhead line on an 8' basement ceiling. Spin on Westwood filter. Check valve on the return. There is a generator that is also fed off of these tanks (don't think this matters, just including any variables.)
When I replaced the pump last night, I set the pressure at manufacturers spec (175 PSI) and did my combustion test. I had a 11.75 CO2, and a zero smoke. I can't help but think that if there were something wrong with the oil my combustion numbers would be way off. I have included a picture of the inside of the pump, which does look somewhat rusted or oxidized, especially for a pump that is only 6 weeks old. Any ideas would be greatly appreciated. Thanks.

AirborneTrav

Scott M_2

If there's rust in the pump there is water in the oil.Someone may have left the cap off the fill or the home owner got a not so good deal on cheap oil.

STEVEusaPA

I think you're pulling too high a vacuum. What's you're vacuum gauge reading at the pump? You're going up 8 feet and over 40, probably too much, probably about 12 inches + of vacuum.
You may also have a partial plug/restriction/kink on your return line. A plugged return line will blow out a pump seal.
If it were me I would eliminate the return pipe, and put a tiger loop at the burner.
On the initial bleed, I would pull the fuel through the filter at the tank, through the fuel line with my hand pump to the Tiger Loop to avoid a lot of stress on the new pump. Then hook up fuel line and let the Tiger Loop do the rest.
I would be interested in before/after vacuum readings at the pump.

Scott M_2

Stick that tank with water paste there's no way a new pump should have rust like that

AirborneTrav

@Scott M I initially suspected water too, but if you think about it, water would settle to the bottom of the tank, and if there were water somehow mixed in with the oil, the combustion readings would be way off. @STEVEusaPA my vacuum reading is only 5, normal for a lift condition like this. I also blew the lines back the last time I changed the pump. I have considered a tiger loop, but not sure it would really do much here.

Scott M_2

Yes it settles to the bottom but remember you have a return line churning that oil up a bit,just saying it takes 5 min. To rule out,and in 30 years I've never seen up pump with rust on the inside not have a water problem especially a new one out of a the box

AirborneTrav

@Scott M fair enough. Definitely something to consider.

EBEBRATT-Ed

seems like water would be the culprit but if there is water in the tank I would think you would see flame failures. Additive?

Robert O'Brien

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northernboiler

You need to find out who the oil company is.
If it is Petro, they may have given him bio-diesel.

I personally know techs that work for them and industry reps that have commented on things exactly like this.

And they all commented that this was a big issue on Long Island (Suffolk and Nassau)

northernboiler

It's just too much of a coincidence that we were talking about this during a training meeting about 3 weeks ago

AirborneTrav

@EBEBRATT-Ed he uses power flow when he gets a delivery. @northernboiler what exactly does bio-diesel do to negatively affect pumps? He doesn't use Petro- I didn't recognize the name of the company he mentioned. I am going to call them and see what they say. Do oil companies use bio-diesel without informing the consumer?

northernboiler

It would not totally surprise me if an oil company gave him bio-diesel without informing him.

And I have personally seen completely seized up pumps due to B20 bio-diesel.

I do oil servicing, however I do no sell oil.
I also am in regular contact with techs from oil companies that do sell bio-diesel. It has personally been described to me as "problematic" and "good job security".


https://www.beckettcorp.com/support/tech-bulletins/becketts-technical-position-on-biodiesel/

http://m.inspectapedia.com/?url=http://inspectapedia.com/oiltanks/Biodiesel_Heating_Fuel.php&utm_referrer=#2901


https://www.suntecdirect.com/pdf/B20.pdf

Oiltankguy220

It's the bio fuel. Put a b20 pump or tiger loop . Problem solved . Been doing it for 11 years now. I clean tanks also , I hear it all day long