Hercules Oatey 35310 Fuel Oil Sludge Treat, 32 oz, White

Over the past 28 years, I had been extremely lax in wellnes/maintenace checks of my oil-heated furnace (STILL am)! I would only call a plumber for it when it didn't perform well (typically every five years) and its malfunctions were almost ALWAYS due to a "tar"-like sludge in the housing-chamber of and surrounding the filter itself of the oil tank.Well, 8+1/2 years ago, I did some research on that issue, which ultimately directed me to this "Oatey" product.Ever since, I have been adding it to my tank, as directed per proportion on the jug, just the day immediately preceding the oil-delivery. This past winter (March, 2024) and remembering the past 5-year time-spans between filter-clogging and realizing it had been at least 8 years since the furnace was last serviced/"broken down," I decided to take-on the project of changing the tank's filter myself (even though furnace was still working FINE).When I did, I could hardly believe the LACK of contamination in that filter-housing, in comparison to those of years-past!! OK, the oil within and the filter itself was dark (much like strong black coffee) BUT, it was totally free-flowing with NO "Sludgy Goop" whatsoever!! I almost felt like I'd wasted my time (and negligible cost of the filter itself) in stinking up my hands and basement with the unnecessary filter-replacement😄You don't need to add much either .. only a mere 1/4 of the 1-quart bottle per 250-gallon tank!Needless to say, I will certainly now continue to add this Oatey sludge-prevention treatment the day before EVERY #2 oil-fill of my tank!

HVAC guy was telling me I was going to need a new oil tank. Started using this product with every tank now he is telling he the tank looks great! Highly recommend

Good for my heating oil tank. I add half a can each refill.

As far as I know, so far so good. I haven't had any problems from residue. I will continue to use it and will have to update periodically. It is also well priced. Only wish it could arrive sooner so that is why I gave it 4 star.2/2018 Update: I failed to put this treatment in my tank last fill up. Needless to say, the weather was below zero and not only did the line freeze , boiler stopped running due to the sludge! frozen house and pipes! Any who, I am back to order this product but see that the price has dramatically increased by 3X!

This stuff keeps our furnace running clean

This stuff actually does exactly what it says it does. I used to have really sludgy fuel filters every time I would change them out but now they never have any sludge on them at all. I just dump a whole bottle in my tank right before I get it filled up. Works like a charm. I highly recommend this stuff.

If you've got an oil burner use this over all others. It's competitors wherever ive gone recommend an entire bottle for an average size tank. This recommends 1/8 a bottle for. You can buy this on average for around 10-15 but even if overpriced you get 8 uses from 1 bottle of this vs the other brands.

Prevents sludge build-up in oil tank. Use at every fill-up to prevent oil burner problems.Does a good job.