Crazy DHW Heat loss! Help!

[deerefanatic]

Hi guys.

I spent this afternoon replumbing my sidearm on the hot water heater in the milkhouse in the barn. Got it hooked up so that it draws from the bottom drain fitting and returns into the relief valve opening. Got everything together, checked for leaks and proceeded to heat the water up. Now, the heater is a Reliance 606 Electric, 50 gallon. I had the breaker off and after about an hour and a half the sidearm had gotten the heater up to about 85F according to the thermometer in the hot water outlet. Ran some through the faucet to make sure the thermometer was correct....... So I kicked on the electric as we were gonna need hot water for chores soon.

Now, fast forward a few hours.... The electric has been on to the heater, in addition to the sidearm running this whole time. Thermometer shows 130F. I shut off the electric, but leave the sidearm running. We go in for supper.

Now, 2 hours later, I go out to see that the wood boiler was down to coals. Water was still 180F. I shut off the pumps for the house and barn sidearms and do some quick rewiring to set the system up for beginning to run off the storage tanks. (I don't have my relays yet to automate the system.) Since I'm already outside, I thought I'd run out to the milkhouse and see what the sidearm had gotten the hot water heater up to. I go out and see the thermometer is at 80F. Strange I thought, but then reasoned that maybe with the new higher efficency stuff, that the water wouldn't rise out of the tank to register on the thermometer. A quick touch confirms that the sidearm is HOT. So, I go and open the hot water faucet........ And lo and behold, the water IS COLD!! I go back and check and the thermometer is still at 80F, and that was ALL the hotter the water was too!

So my problem is where on earth can all the heat in 50 gallons of water go in a mere 2 hours while the sidearm is STILL RUNNING?

All the hot water pipes go to faucets, which were all turned off with no drips. No mixing valves or things like that where water could be back feeding to other places.. And while I know that the reliance isn't the best insulated unit on the market, I wouldn't expect it to cool off in 2 hours. Especially when the sidearm is still running..

I'm beginning to see why our electric bill for the farm is $300/month, even now that we're only raising a handful of cows and not milking full-time......

 

[kabbott]

The only thing that comes to mind other than a leak somewhere would be if the dip tube fell off and the water was going strait from the inlet to the outlet.
I was not sure about the whole sidearm deal until I made my own and I have to say it works great.
It will raise my 40 gallon from well temp to 130-140 in 4 hours give or take, and 24 hours later it is still hot enough for showers. This is on a ~30 year old electric heater.


I will start a thread with some pics of it, I slapped it together with silfos and a TIG torch, only 2 fittings (3/4 female adapters) very cheap.

 

[Nofossil]

Not sure I got all of this, but any chance that your sidearm was thermosiphoning heat AWAY from the DHW? When there's no intentional flow through the boiler portion of the sidearm, check the pipe temps a foot or two away from the sidearm. Thermosiphoning can be devilishly ingenious about finding ways to move heat.

 

[deerefanatic]

Well, the boiler water had been running continuously the entire time...... Right up until about 30 seconds before I went and checked it..... So I was trying to HEAT UP the hot water heater........

As for the dip tube falling off.... I am pretty sure it's still there..... When I was filling the hot water heater back up, I could hear water spraying around inside for about the first minute, then it went away and I could just here the water gurgling into the tank. So I assume the dip tube is working fine. Plus, when using the electric, it puts out hot water just fine....

 

[Duetech]

That sounds familiar to the problem I had. Old hot water heater and a side arm. My boiler water goes through the sidearm from my secondary which runs a basic 24-7. I had flushed my water heater before hook up so I thought that was ok. About 3 days after start up the dhw temp started dropping noticeably and by one week finally got too cool to shower. I re-flushed my aged 40 gal hot water tank and got more crud than I did before hook up. Now my tempering valve is the only thing that keeps me from getting burned and the showers are hot and I have neglected to flush the water heater since. Flushing might be worth the effort as old as your heater is. Just a thought...

 

[deerefanatic]

I'm thinking I do need to flush the tank again. The sidearm doesn't seem to be thermosiphoning... BUT, that still doesn't explain how on earth that heater could have cooled off in only 2 hours.......

 

[Duetech]

No it don't, not on an electric with the exception of a leaky hot water faucet/pipe where cold water is always cycling into the tank and is not getting heated because the sidearm is restricted. That would be one huge leaky piece of plumbing. For grins turn your pump off and don't use the water for half an hour and see what happens to your pressure. You have a puzzle. Please keep us posted...Cave2k

 

[deerefanatic]

I'm going to try your suggestion today and see what happens. I think I may know.... We had two washer units (pipeline washer and bulk tank washer) for the milking equipment. They connect to both water lines. I'm thinking one of them is allowing water to short-circuit from the hot to cold when the cow water trough runs water. So I'm going to check into that. We shut off the water supplies to both of them already. So I'm going to flush the heater and see if the side arm will actually heat it up and keep it hot.

 

[Snicks]

How is your side arm plumbed into your water heater. Sounds like it gets air locked (on your domestic side of the side arm) so it wont thermosiphon properly. When I install them I put a tee in the bottom of the water heater were the drain valve go hook the side are into that and then the valve back in. the top of the side arm should hook in to the top and side of your tank were the popoff is with anouther tee. If you have to hook in on the very top of the tank were the water comes in and out of your tank then you can have the problem that sounds like your having it gets air locked (Not in all cases but some). 2 ways the fix that problem run 2 tees on the top side of your water heater and put in and air blead. The other way is to use a recerculating pump on ether side of that side arm ( I do this on realy high demand systems any ways) ( A hotel that I installed and out side wood boiler at. I used a recerculating pump on a 150 gallon water heater on the side arm. works perfect) .

just a thought.

I want to build in indoor hot water storage tank in my basemen. Not sure how im going to do that yet. I have been reading alot of diffrent ways on here and other places on the internet. I worried about humidity in the house with a tank in side??


Well thanks,

 

[Eric Johnson]

You have to seal the tank up pretty good, Snicks. You need a vent tube, but that's about it.

 

[88rxn/a]

You have to seal the tank up pretty good, Snicks. You need a vent tube, but that's about it.

could you explain this a little more please?