Stuck water heater overflow valve

[imiloa]

I have an aging Raritan water heater (6 gallon like model 170601) with a stuck (REALLY stuck) and leaky overflow valve I'm trying to replace. The unit is very hard to get to and I cannot get a "come-along" onto a wrench to get enough leverage to loosen the thing. I've tried Liquid Wrench, PB Blaster, WD-40, you name it and I can't get the valve to budge. Does anyone know enough about the innards of this kind of heater to tell if heating the valve with a torch will damage anything inside? (I'd really like to replace the heater enirely but I'd have to either remove the engine or cut the lazerette opening in the cockpit bigger to do that. Neither of which is a good option right now.)

[deniseO30]

You didn't say what boat you have.

I had the same heater.. best to get a new one.. you will find out it's bad because they had glass lined tanks. There will a be sulfur smelling like sludge on the bottom. I find it hard to believe you would have to cut the boat to get it out. You can remove the jacket and make it smaller. or even cut up the old tank. A new one that is rectangular would be a better choice. heating the tp valve may help but you still need a long handle pipe wrench remove the tp valve. DO NOT PLUG THE VALVE FOR ANY REASON!

[svHyLyte]

The most common cause of Pressure Relief Valve Failure is debris caught in the valve. The most common source of debris is the breakdown of the annode that is part and parcel of the hot water discharge valve and I suspect, given the installation you describe, the annode has never been checked or replaced and is likely completely wasted. If so, replacing the pressure relief valve without replacing the annode and cleaning the black guck it's become out of the bottom of your tank will simply result in the new valve becomming stuck.

As to your specific question, the tank itself is thin-wall stainless steel. It is wrapped in fiberglass batting and that covered with a painted steel shell. Heating the valve is not likely to damage anything but the valve itself, nor is it likely to free anything up. The following is a link to Raritan's replacement instructions: Raritan Engineering | Repair Shop Where there is a will there is a way.

Cleaning the tank itself involves removing the hot-water discharge valve (see Raritan Engineering | Repair Shop ). I found that alternately shooting water into the tank and then suctioning it out through a 5/8" diameter hose connected to the hose from a shop-vac eventually got most of the material out but it was a tedious process requiring many repeated partial fillings and then evacuatios. (See Raritan 1700 Series HW Heater - Cruisers & Sailing Forums ).

Good luck.

[Maine Sail]

Originally Posted by svHyLyte

As to your specific question, the tank itself is thin-wall stainless steel. It is wrapped in fiberglass batting and that covered with a painted steel shell.

Actually:

• Glass-lined steel tank is more durable than stainless steel.
• Attractive polymer jacket resists corrosion from dampness.

More durable than stainless my arse!!


The Raritan tanks, IMHO as somone who used to be a rep for a tank manufacturer and who wrote hundreds & hundreds of RMA's for "cheap" glass lined tanks, are of a poor quality for the marine environment.

I have yanked many Raritans out that were complete piles of rust. Unfortunately torquing on the T&P will only cause you to potentially flex the steel vessel then fracture the glass lining. Once the glass lining is voided the tanks rots out in no time.

There is a high likely hood that the reason the T&P is plugged to begin with is because the tank is rotting or there is lots of crud in it. You really need to use a pipe wrench and also support the nipple for the T&P at the same time so you don't flex the vessel.

If you do find that the tank is gone the Heat Transfer Products "Super-Stor" line of water heaters are excellent tanks as are the Iso-Temps. You actualy get your moneys worth with a Superstor or an Iso-Temp but you pay WAY to much for the quality you get or don't get with the Raritan..

You really need to find out what caused it to open in the first place. It would have to get very, very hot in order for that to happen and we know, unless you were pressurized dock-side by city water (a no-no in and of itself), that it did not pop of on pressure...