Hot water heater Hot and Cold hookup


I’m looking for some information that shows why there is a hot and cold water hook-up on each hot water heater.

According to some plumbers it makes not difference which side is for what.

If this were true, a water heater manufacturer would not label the cold and hot location on the water heater.

In addition, why bother with a shut off valve if it doesn’t matter which is in and which is out. Some of the plumbers say either side is OK.

Some plumbers are not very clever.
You are supposed to install equipment as the manufacturer intended. Water heaters heat water most efficiently when the water is going through them as designed.

The cold water entry goes into a pipe to the bottom of the unit where it is heated (heat rises). The hot water exits from the top.

If the pipe were reversed the hot water would draw from the bottom where the colder water is.

Some plumbers are “plumb loco”.

Read the manufactures specs…

image post malfunction. Danger Will Robinson.

Try it now.

I concur…

Your illustration is prettier than mine but mine has got discrepancies to make it more realistic. i.e. no extension tube on the TPR

Any diagrams for this one fellas?

You are not going to trick me into telling someone how the internal piping of their water heater looks/works without me seeing the the manufacturers drawing/schematic.:slight_smile:

I see more than just a missing TPR extension. I envision both of the pictures as being in the attic–with no drip pan…

…or they’re in a crawlspace and no concrete under them–they’re in the dirt…

…or they’re actually drawn sideways–both units are installed horizontally with an exhaust fan in the chimney drawing the flame into the heating tube and out the chimney…

…or they’re not really water heaters. They are extraterrestrials in that form so they can spy on us. (See the UFO thread)

…and now I’m going to take my medicine…

…who are these guys in the white coats???

Jae, that’s one of those plumbers cracks.


Are you feeling Ok?

Here ya go…

Pretty clear, succinct, and to the point.


Plumbers cracks are what is seen from behind when they are squatting down. :mrgreen:

Sorry, Jae. Had to do it.

I have, recently, been running into a some of fmy ormer clients who call me to complain. They have HVAC guys come in to do maintenance on their furnaces (most that I inspect have not been looked at in quite a while and I recommend maintenance) and they tell the client that the water heaters are spewing forth CO. Of course the client panics and the HVAC guy is right there to slap in a new water heater.

  1. In my area, water heaters are a plumber’s job, not an HVAC guy. What about in your areas?

  2. The clients are, usually, quite P*SSED and want restitution. I have been called back a few times when the HVAC guy was still there and re-inspect the drafting and such, but find nothing. The HVAC guys are usually really indignant. “Who you going to trust, a home inspector or an HVAC professional”, they say. Puts the client in quite a bind. I usually refer them to a good plumber who comes out ans tells they that everything is OK.

Have you been seeing this scam in your areas?

Only a licensed plumber may legally install a water heater in this neck of the woods.

I saw a great termite inspection today. The termite guy got there 15 minutes after me, talked with everyone for 15 minutes, said the house had to be tented, and left. Hmmmmmmmmmmmmmm. His company is now on my “Do not recommend” list.