Print

[Scott7m]

Sounds like you have a bad mixing valve then...  Seems you have hot water everywhere besides where you need it

[Scott7m]

He said he drained 3 5 gallon buckets out of the tank and it was scalding.....

[SperleFarms]

Thanks for the help guys, I'll post an update when I figure this thing out.

[RSI]

If the water in the tank is hot then it is the mixing valve.

[willieG]

 mostly i think as rsi it is the mixing valve but i have some things i am uncertain of..couple of thoughts what do you guys think?

the cold water supply is likley on a dip tube about 2/3 of the way down the tank.

the way the thing is set up to siphon i have a feeling it may only create hot water to the level of entry as there is no reason for the siphon effect to continue?

if there happens to be even a short dip tube on the hot side it may be just at the level where the water is luke warm?

i would either take the mixing valve out and try it that way and if this still does not work...eliminate the whole siphon effect and  make it with a couple of valves to either feed the tankk from the top (as designed) in summer and close a valve and open a valve and feed the cold supply into the plate exchanger  and forget about having the tank as reserve.

[RSI]

I think you may have already mentioned this but I don't want to read over the whole thread again right now.

Was it working ok with the gas heater running? If it was then it probably isn't the mixing valve and it the problem was there then it is the mixing valve.

I have never seen a dip tube on the hot side of a water heater. If someone put it in the wrong with it will not work right.

[SperleFarms]

New valve installed, we’ve got hot water coming out our ears.  Problem solved, for now anyway!   

[Scott7m]

Sounds good!  I was gonna be shocked if that wasnt the problem

[oldchenowth]

I amno expert like most of these other guys, so I will teel you the way I did mine w/o a circ pump.  I disconnected mine before the cold inlet side of the water heater and forced it to the plate first, back to the inlet side of the heater.  Mine is AFTER the forced air HX to make hot water with no (I know "stupid".  I take full responsibility) mixing valve.  Turned the breaker off and have unlimited hot water.  Just my $0.02

[ghitch75]

if you want true control of your water heater with a OWB it needs a stat.....i use a plate heat exchanger,007 bronze pump,aqua-stat and a zone valve.....you pull water from the bottom of the tank threw the plate and in to where the TRV goes.........there is a well in the tee setup in the drain port to where your aqua-stat probe goes and when you set the stat for 120 you get 120 no guess work..........side arms should not be aloud to be sold!!! ......worked on and replaced tons of  mixing valves in schools and other places(pipefitter for 20+ years) as when they fail you get burned!!!....so when i started sellin' OWB i came up with a better and no way to get burned......here is a pic of mine...hard to see all of it....

[Scott7m]

That works fine, but lord help the person if they ever need to replace that hot water tank..

I install 20 plates with 1" ports and use various pumps depending on the job, I've never had an issue of water being to hot or to cold, everyone seems to love it.  Also I've never noticed my cold handle on the shower needing to be in different positions, so it's pretty consistent

I agree about mixing valves, don't like them

I just like to keep things as simple as possible... 

[dwneast77]

Scott, I agree with you.  I recently found myself in the position of "what to do?"  I really like the way ghitch set his up and I had been thinking that I would do about the same, usuing a pump and aquastat for the most consistent temp.  The almight dollar won the fight and I ended up just plumbing it in to the incoming line, figuring I'd be keeping a close eye on it for a while.  So far I can't be happier.  I'm still a little uneasy about the high water temp flowing into the water tank.  I installed an in-line thermometer.   It does depend on water volume being drawn.  For example at prolonged light volume usage the water temp flowing into the tank is around 160 to 170 and that would increase the tank temp.  I do notice my water temp rise while in the shower and I have to adjust the cold.  I'm used to this as it always happened mid-shower with oil burner as that always kicked on while showering (I could hear it) (oh, by the way, it's great NOT to hear it anymore  ).  When I fill my washing machine which is located right next to the water heater, the temp flowing through the HX drops to around 140+ which is still higher than what my original heater set point is.  Boiler runs 185-190 with 009 pump pushing about 125' one way to 10 plate HX and then forced air HX.  I have no complaints with this setup.  009 may not be real fast, but it is a workhorse and has been for 5 seasons now. 

ghitch -  If I were to install as you did, where do you position the temp probe from the aquastat??  That was my biggest question.  My local true value plumbing guy (who I'd trust with just about anything) suggested cutting through the outer shell and using a strap-on type aquastat to try to get the truest tank reading.  I figure if the probe is located somewhere in-line then the line would cool more quickly causing the pump to short-cycle often.  Just my thought on it.  I'm curious.

Jeff

[Scott7m]

Yea if you let it trickle it could get hotter, but under normal use, I love it

[ghitch75]

i took a pic of the tee setup......i took a 3/4" brass plug and drilled a 3/8" OD hole in it and silver solder a 12" 3/8" copper pipe to the brass plug and sealed the end......as in the pic you can see the probe from the aqua stat in it......it will sense the water temp when the pump pulls the hot water to the bottom of the tank and push's the cold the threw the HX and dumps the hot in the top of the tank.....

btw....this is in the 10th year runnin' with no parts replaced(knock on wood!!!!)

[dwneast77]

ghitch -  That is a pretty ingenious idea.  If I read it correctly you have a 3/8 x 12" copper pipe slid into the 3/4" so that the probe is actually within the tank?  That's a cool idea.  Setup basically how the aquastat on my Wood Doctor boiler is set up.  Has a tube welded through the wall that the probe sits within.  Better and cheaper than the idea I had using the strap-on aquastat.  I just bought one of those Johnson A419 aquastats so I know it would be cheaper than the strap-on one my true value guy has to offer.  That was about $130.  He just got me the A419 for his cost of $82 with UPS charge. 

Thanks for the pics and idea!!!

Jeff