HOW TO LOOK AT A WATER HEATER
This “article” began life as a worksheet, tied to the Water Heater Workbook. For years, I’ve been teaching classes on how to understand the life and death of water heaters. We do this by catching heaters on their way to the dump and then taking them apart. Sometimes fun tools like the Sawzall or really big pipe wrench get used. It’s instructive to actually see what happens to heaters over time in different conditions. You can even tell how much or how little the people who came into contact with the heater during its life, knew.
We start by figuring out how old the heater is, because you would expect different stories from a four year old heater than a forty year old one!
1) DETERMINE THE HEATER’S AGE This is done by looking for date codes on the heater itself, or the relief valve or the controls. Sometimes there is even a date code on the dip tube, inside the tank. Some of the main codes are: A81 means January of 1981, B81 would be February and so on. 181 also would mean January of 1981. 281 would be February. 8101 would be the first week of 1981, while 8152 would be the last week of 1981. Bradford White has their own code, which is available here: https://www.bradfordwhite.com/serial-number-date-code-reference-100#
2) LOOK AT HEATER FOR CLUES ABOUT DRAFTING If it’s a fuel fired heater, this can tell you how well the heater “breathes” and how safe, or not the heater is. If you see evidence of backdrafting, that means carbon monoxide may be getting into your living space. Not good!
Do you see any of these things?
Corrosion on the flue side of the nipple? (A clear indicator of backdrafting)
Melted insulation at the draft hood? (Same as above)
Ring of rust or discoloration on top of heater? (Acidic condensation may drip down onto the heater, causing a ring of rust, it’s a sign of poor draft)
Discoloration or soot around combustion chamber door? (This is where flames or hot gasses leap out of the combustion chamber, suggesting a blocked flue or other problem.)
3) LOOK IN COMBUSTION CHAMBER
Do you see any evidence of leakage in combustion chamber or flue? (This matters because there is no point in working on a tank that has already failed. This also is a first clue about the condition of the anode inside of the tank. If you find heavy or wet rust, the tank has leaked and is not worth fixing.)
4) REMOVE ANODE AND ASSESS CONDITION
Use: torque multiplier. (This is a tool that pros use as it works and helps prevent unnecessary strain on the person doing the work. Removing anodes can be challenging and having good tools really matters. Once the anode is out…)
Is the metal on the core wire depleted? (This lets you know how much life the anode has left.)
Is the anode magnesium or aluminum? (Aluminum is soft, easy to bend. Magnesium is stiff and a bit springy. I don’t like aluminum in tanks as I think it’s a health risk that we don’t need to take.)
Is it hex-head or a combination type? (If it’s a hex type, that means you could add another anode in the hot port!)
Is there anything unusual about it? (Here we’re looking for “passivation”, which basically means the anode has stopped working, or other stuff, like the rod being split, or chunks falling off.)
The ideal time to replace an anode is when six inches of core wire is exposed, the rod has even wear and is not coated over with a hard calcium buildup.
5) REMOVE OLD DRAIN
Use: crescent wrench & basin wrench; you may need a screw driver, hammer & rag. The first two tools are for removing the drain valve. The others are for removing any plastic remaining from the valve and for preventing much water from pouring out once that valve is removed.
What sort of drain was the original equipment? (The best drain is a full port ball valve. Between the tank and valve, you want a lined steel nipple and at the outlet of the valve, you want a hose adaptor.)
What, if any, difficulties were encountered in removing the old drain?
How big an opening is provided by that drain? (It’s fun to try and look through some factory valves. With some it’s hard to see how water or sediment could ever get through)
6) REMOVE NIPPLES ON TOP OF TANK
Use: pipe wrenches, including ratcheting type; you may need a hammer & chisel
What condition are they in? The point here is to see two things: are the steel nipples clogged up with rust, slowing flow and is there enough rust to weaken the threads, increasing the risk of leaks?
How does the tank look where they were attached? (Rust is the enemy!)
7) REMOVE DIP TUBE
Use: channel locks. This is done by sticking one handle of the tool down into the dip tube, then wiggle it around and pull up at the same time.
How does the dip tube look? Here you’re looking for cracks in the plastic, or holes, or even some or all of the tube broken off and missing.
Does it have any cracks or holes? If so, the cold incoming water will mix with the hot and give you a luke-warm shower :~[
8) TRY T&P LEVER TO SEE HOW IT FEELS: THEN REMOVE IT
Use: pipe wrench
Look at the back of valve to assess amount of sediment build-up.
Blow through it. If that doesn’t work, clearly a new valve is needed. This is really important as the relief valve is the last line of defense against the heater blowing up if things go bad.
This has been just a brief overview of how to look at a water heater. For a heater still in service, these steps will tell you if the heater is worth maintaining and how safe it is or isn’t. There is a lot more info at www.waterheaterrescue.com
Looking back over my working life of 50+ years, it seems clear that self sufficiency has always been the best way for me to be useful. Now, mix in a strong interest in water in its many forms and the wide world of animals and you'll know what's important to me.