Roth tank issues 2

The recent Roth tank thread got my attention since a few weeks ago the G-115/21 with Riello F3 .50 Delavan nozzle stopped working due to a crimp or blockage in the oil line. Tech found carbon on the head, burner stuck on pre-purge, no ignition. The suction assembly was changed. Nozzle, O-ring and burner 10 micron filter were changed, but there was no evidence of problems with those. (This is a single line feed to burner.) I contacted Roth and got some answers relatively quickly; the tech said he would post on this thread but he hasn’t gotten around to doing that yet. So I’ll synopsize what I heard:

They believe that some of the problem involves oil quality (sludge) and additives that contain Napththa— a prime ingredient of cold weather additives, especially in Long Island and New York State. It causes the hose to swell in percentages greater than 35%. He was very clear that their suction assembly does not float (my tech had said he replaced the ‘floating’ suction assembly). Floating could be a sign of malfunction. Roth’s suction assembly has a weight on the end that keeps it at the bottom of the tank. My tech replaced the half-inch tube with a 3/4”; Roth recommends 3/8” fuel feed, the size of their suction assembly for most residences. The use of 3rd party equipment is discouraged and in some cases can void the warranty.

Roth sent me a bulletin from 2003 about suction assembly failures. The problem of the suction foot slipping off has been resolved with the addition of a hose clamp; the problem with tubing collapsing under vacuum has been traced to the aforementioned fuel additives, which can also cause seal failures on air shutter pistons due to adverse affects on rubber products. Additives containing napththa should not be used. As an option, suction assembly may be replaced with a ‘hard-piped’ copper suction line and duplex bushing as in standard steel tank installation. In that scenario, the fuel additives do not appear to be a concern. The manual also says that additives added by the distributor in bulk before loading into the delivery truck do not seem to be a problem.

I’d like to hear what you experienced oil and burner guys have to say about this; we really can’t afford to have nuisance burner outages like this. I am thinking of asking my service company to hard-pipe a copper suction line for a long-term solution. Any adverse affects of this? I assume we’re talking about the inner-tank line and not the rubber one from tank to burner.

Thanks,

David