Is it time to replace my outdoor oil tank? (Urgent)

The old oil line connected to the outdoor tank should be completely eliminated and removed. Seal the hole. Brand new coated oil line from the new tank to the burner, with a new oil filter complete. Not just the cartridge.

IDK what you mean about "4 pipes in total coming out of my house". The fill and vent on the existing outside tank will be gone when the tank is gone. You'll have one new fill and one new vent poking out the side of the house. That's it.

Yes it would.

A Highland Petrohopper is a steel oil tank that is secured in an outer tank. You could buy more oil than you would typically need and save money in the process and have excess oil for an extended period if you are stuck without a regular delivery due to a snowstorm.

Conventional wisdom is to leave them full. I recently took my 20yr old exterior tank out of service (replaced with Roth) and had the need to cut a 2x2' panel out of the side of it, so I ended up being able to take a look inside. It's been standing up on-end for nearly two years, so the bottom is nicely dried out. When I hit it with a hammer, it sounds like good metal. Visually, only the slightest of flash rust which I could probably remove with steel wool. No roughness or 'rot' that I can see.

I attribute this to having the tank tipped towards the outlet and always running it dry. In the summer, maybe any slight condensation on the interior managed to run down into the copper line (which had been somewhat evacuated by the burner pump). Just my experience, anyhow.

If you have a oil fired WH your probably not going to run out of hot water. If it was me I would make heat the priority. It's more important to keep the house from freezing.

Your above post said the Roth would not fit down your narrow hall???? So are you back to the Roth or the Granby?

also, no one has answered the question or speculated as to why an outside tank was installed previously instead of an inside tank.

I know of no jobs where an outside tank was installed when a tank could have been installed in the basement.

Granby also has 120, 138 and 240 gallon tanks

I would use a priority relay if using overhead lines. The alternative is to use a separate overhead oil line to each appliance and a common return. That is what I would do. and eliminate the priority relay

@Intplm.

Why are Roth tanks so great?

I genuinely don't know, and I'm sure many that come across this thread won't understand either.

The only thing I know about them is they look like little outhouses and everyone loves them.

A priority relay that is activated by the orange wire of the water heater burner's primary control is the best way to do this. We have used this when we need to vent two oil burners into the same chimney and discover that the chimney can not handle two burners operating at the same time. Relay is less expensive than a second chimney in most cases.

Same holds true if the fuel system can not handle two burners operating at the same time. If the relay is less expansive than the repiping or other fixex, then the relay is the best answer.

Look at all your options. and select the lowest cost one. Relay or fuel line repairs/replacement. Can your existing fuel line used as a 2 pipe system handle 34 Gallon per hour flow rate? that would be the gear set capacity of a typical mini pump like the Suntec A2VA series of pumps (times two).

With a Riello burner on the water heater tank, you do not just place a relay on the orange wire, like I said earlier. The best advise I can give you for the relay connection is to place that relay coil in the L terminal which is the same as the 5 terminal on the primary control tab. Then use the normally closed contacts on the relay to break the limit wire to the primary control on the space heating furnace or boiler

From the photo you posted, I can not see if that relay is there. You might need to remove a cover from an electrical box, water heater temperature control or the riello burner cover to reveal that. I can tell you that if both burners operate at the same time, EVER, then you do hot have a priority relay on the water heater.

You could try this piping arrangement. Since the water heater runs all year at least a couple of minutes every 6 hours or so. The tiger loop will get exercised daily, you can depend that any small amount of air that might find it's way to the burners, will be deaerated regularly. If you place a Tee fitting between the filter and the tigerloop and make sure the branch of the tee is not pointing UP, so air can't float into the space heating line. than you can be pretty sure that the space heating burner will not get air bound and need priming on a regular basis.

If that fails to work than you can add the second tiger loop later if needed.

@EdTheHeaterMan two burners and 1 suction with lift will never work. One pump is always stronger and the burner will fight each other for oil and one will always loose. People in the past would try and fix it with check valves which didn't work. Putting one burner on priority might work. With one overhead line??? wh knows it may work or it may not. If the oil is actually syphoning so there is + pressure at both burners it might be ok (especially with a full tank. Throw TLs into the mix not sure what that would do. Oil lines always were a PITA

You are correct if you live in Pennsylvania, New,Jersey, lower parts of New York state where the normal cold temperature rarely goes in the the Below Zero°F overnight. In the more northern areas where below zero is a normal occurrence, maybe not so much. Although there are many additives to keep your oil viable in those temperatures, I have found in my little area of the world, Southern New Jersey, There are some fuel oil in some tanks that will always have problems that will cause burner failure that are self correcting once the temperature rises above that problem threshold.

I can say from experience, If the weather forecast called for temperatures below +17°F, I was guaranteed at least one no heat call as a result of the fuel tank temperature. It was usually a new customer that was unable to get a fuel oil dealer to respond "because you don't purchase our oil". I would then recommend something like a tiger loop, or tank maintenance, or a Scully Snorkel tank gauge with a fuel surface pickup line. Then I would recommend one of the 5 oil dealers that did not have a service department, who recommended me to their customers.