Water Heater Plumbing

[chasineyes]

So we recently purchased a small cabin and last weekend while analyzing things, I noticed they have a line plumbed in between the HOT and COLD supply lines to the heater with a shut off valve.  Any idea what this would be for?  I understand having a cold water supply and then the outlet for the hot water but why "join" the two 6 inches above the water heater??

[MNsetters]

It's a cabin, so probably not heated in Winter. Drain water heater,and use bypass values to add antifreeze or blow out water lines

[delcecchi]

guessing maybe to allow bypassing the water heater if it were ever needed?  Winter, or in case of a leak?  

[Juneau4]

If I understand this: the hot and cold lines have a cross pipe between them with a shut off valve on the cross pipe so it looks like the letter H with the water heater on the bottom of the legs of the H.

 

If that is true, the person who plumbed it had no idea what they were doing. If the valve is open you won't get as hot of water as you should and if it's closed it's the same as if it never existed.

[PurpleFloyd]

Doesn't make sense if it's a water heater. I have had boilers that were plumbed like that but not water heaters. Is there any kind of circulating pump hooked up anywhere that requires a constant loop? Even then you wouldn't want to be hooked to the cold line. 

[Cheers]

I would guess it is for winterizing the cabin to enable blowing out lines

[chasineyes]

7 hours ago, Juneau4 said:

If I understand this: the hot and cold lines have a cross pipe between them with a shut off valve on the cross pipe so it looks like the letter H with the water heater on the bottom of the legs of the H.

 

If that is true, the person who plumbed it had no idea what they were doing. If the valve is open you won't get as hot of water as you should and if it's closed it's the same as if it never existed.

You are correct.  I kind of figured if you have the valve open you're just mixing cold with the hot water, so I shut it.  We plan on heating it all winter so we can enjoy it during the best time in Minnesota!    That's just my opinion though...

[RebelSS]

That's incorrect and absurd. A proper install is with a ball valve 8-12" above heater on incoming cold water line. You're sure it isn't a DEU he threw a valve on?

[Surface Tension]

 I'm stumped on the crossover w/ valve.

Stumped on what a DEU is too.

[delcecchi]

Only reason I can think of, upon pondering for a while, is possibly to enable running the water system without the water heater.  But if that is the only valve, it wouldn't do it.  I am pretty much stumped.  

 

They put those bypass valves on water softeners.  

[RebelSS]

29 minutes ago, Surface Tension said:

 I'm stumped on the crossover w/ valve.

Stumped on what a DEU is too.

 

Dielectric union valve, ST. New codes require (in some places) one between the cold and hot pipes to prevent galvanic corrosion....one side copper, the other steel, with a non-contact rubber washer. Some plumbers just use the ol' clamp and wire system between. Look around if you have an older house, you may see a clamp on a cold water line with a heavy wire going to a ground...mine goes to the electrical box panel ground. 

I think the "plumber" was a shade tree fixer-upper cobble artist.  

[delcecchi]

OK

[chasineyes]

On ‎11‎/‎27‎/‎2016 at 9:24 PM, MNsetters said:

It's a cabin, so probably not heated in Winter. Drain water heater,and use bypass values to add antifreeze or blow out water lines

 

That makes sense.  If you flush the system with antifreeze, this will allow the chemical to flow through the system and not into the water heater.  I assume you wouldn't want antifreeze in the water heater??

[Juneau4]

Quote

46 minutes ago, chasineyes said:

 

That makes sense.  If you flush the system with antifreeze, this will allow the chemical to flow through the system and not into the water heater.  I assume you wouldn't want antifreeze in the water heater??

 

If its the way you described it and the way I understood it --antifreeze will still go into the hot water heater.

Gas or electric heater?

[MNsetters]

I'm sure it also has shut off values on water heaters water intake,and output.

[Moon Lake Refuge]

Hard to tell without a pic or good description but its very common on cabins to be set this way.  The H is usually just a bypass, weather store bought or home made.  There can be a valve between the pipes and one on the in and out.  This helps if you want antifreeze in there but also for blowing out lines.  This allows you to blow out the lines without pressurizing your water heater.  

[PurpleFloyd]

It's probably safe to say it doesn't have any purpose that requires it to be there. It could be left shut or cut and capped off and nothing would interfere with the system. 

[Walleyehooker]

Like Moon Lake said just a by pass for winterizing. Similar to a RV setup.