Strange way to plumb a water heater?

[LastChance]

We have an issue with the water heater on our 300 Marlin. The heater seems to heat the water but little reaches the faucets. I've done all the electrical checks and the high limit switch, thermostat and heater element all seem ok (or at least have continuity). Here's the question:

Why would they on the water heater plumb (with a T) a small bypass line from the cold water intake to the hot water out? I can see no point in this "cold water jumper". It might explain why the water in the tank is hot (I got 6 gallons of hot water spill out when I removed the heater element) but we only get cold water at the faucet. I suspect the bypass likely is preventing the hot water from leaving the tank. I must confess I'm no plumber but this one's got me stumped. One more thing; when you open the nylon drain valve on the water heater, very little water comes out, even when the tank is full.

Any plumbers out there?

 

[DennisG01]

Is the T-fitting too small to be some type of temperature control that has failed?

Are there any other fittings in the lines such as turn-offs for winterizing?

Do the two T's match the rest of the fittings?

Any pics?

As far as why no water drains... 1) Drain is clogged with sediment just like a home water heater. Open it up and stick something thin in there to loosen things up or 2) Try just opening the pressure relief valve

 

[LastChance]

I found it. It is actually a winterizing bypass. What threw me was I couldn't find a shutoff valve for the bypass line. As they said on Captain Phillips

"Hey Irish; everythingonnabeokay"

 

[ElyseM]

a by-pass may have been installed for winterization. without the by-pass, you have to fill the entire water heater tank in order to push antifreeze thru the system. GW does not recommend by-passes (probably for this reason). you need to make sure the by-pass is in the position whereby the feed goes into the water heater tank. good luck, ron

 

[DennisG01]

As they said on Captain Phillips

"Hey Irish; everythingonnabeokay"

Don't spoil it for me! I haven't seen it, yet!

It's funny, I almost didn't even suggest that it was there for a winterization bypass. I was thinking to myself "Self, the distance between the two lines can't be more than about 8 inches... how would one miss a shutoff valve?" :roll: