# Recirc cross over?



## voltatab (Jan 2, 2010)

I installed a water heater in a home, and got a call a couple days later that they have Luke warm water that eventually runs cold and warm water in the cold side of they're master bath, spare bedroom and kitchen. 

The other end of the home was fine. (Laundry, and 2 more baths. )

They had a Recirc that was currently off(timer mode) so I turned it to continuous run and the problem went away. So problem solved I guess but I can't figure out how a Recirc being off would cause all these issues....and with only one side of the home!


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## rocksteady (Oct 8, 2008)

If it goes away when the pump is running 24/7 I'm thinking a check valve is bad or missing.






Paul


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## Widdershins (Feb 5, 2011)

voltatab said:


> I installed a water heater in a home, and got a call a couple days later that they have Luke warm water that eventually runs cold and warm water in the cold side of they're master bath, spare bedroom and kitchen.
> 
> The other end of the home was fine. (Laundry, and 2 more baths. )
> 
> They had a Recirc that was currently off(timer mode) so I turned it to continuous run and the problem went away. So problem solved I guess but I can't figure out how a Recirc being off would cause all these issues....and with only one side of the home!


 Sounds like a missing or improperly located check valve to me too.


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## voltatab (Jan 2, 2010)

Ah. Makes sense. - thanks guys.


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## Optimus Primer (May 20, 2009)

voltatab said:


> Ah. Makes sense. - thanks guys.


you took that pesky check valve out, didn't you? :whistling2:


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## voltatab (Jan 2, 2010)

No sir , not me


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## Richard Hilliard (Apr 10, 2010)

bad check valve or missing and open all the way throttle valve.


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## Widdershins (Feb 5, 2011)

house plumber said:


> you took that pesky check valve out, didn't you? :whistling2:


 I've had to come in a few times and move check valves to the correct location.

I've seen quite a few where the installer teed into the H/W tank inlet *before* the check valve instead of after it.


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## voltatab (Jan 2, 2010)

Ok well HO just called me. Problem is still happening with Recirc on. 

Btw, this is alittle wierd but the home has two water heaters tied in-series of eachother. Cold water main into one, then the hot outlet of that heater acting as the inlet of the next one. That's a first for me. So, two 40 gal side by side 

The one I replaced is the one that did not have the Recirc tied into its drain line. 


They never had an issue before i replaced heater

I'm going back out Friday morning to check it out. I told them the Recirc may need replacing....?


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## Plumbworker (Oct 23, 2008)

you should be able to isolate the return with a valve completely then you know if the return is the issue.. im also thinking you should inspect the dip tube on the new heater?


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## voltatab (Jan 2, 2010)

Thanks I will check the dip tube and isolate the return. Trouble is it's a little bit of an intermittent problem apparently. 

Ive never seen a home have such an issue just because of a check valve....


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## plumb nutz (Jan 28, 2011)

First off, it sounds like you have a bad cartridge somewhere in the house and its crossing over from there...

Second repipe the heaters parallel so both heaters are used and feed recirc. line through both boiler drains...


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## voltatab (Jan 2, 2010)

So re plumb it so cold water is actually water for both WH cold inlets and combine the two WH hot outlets into the hot water to the house, correct? So now both get the same amount of use instead of one getting to do all the work. And then tee the return into both drains , Yeah?


As far as a bad cartridge, it seems an odd choice due to the timing of it all
Also, because I've yet to personally run into it, how can a bad cartridge really flows that much water through it and wreak so much havoc? do you have an example of how this happens?


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## Plumberman (Jul 7, 2008)

voltatab said:


> So re plumb it so cold water is actually water for both WH cold inlets and combine the two WH hot outlets into the hot water to the house, correct? So now both get the same amount of use instead of one getting to do all the work. And then tee the return into both drains , Yeah?
> 
> As far as a bad cartridge, it seems an odd choice due to the timing of it all
> Also, because I've yet to personally run into it, how can a bad cartridge really flows that much water through it and wreak so much havoc? do you have an example of how this happens?


I just took care of a call at a commercial account with similar problems.

There wasn't two heaters tied together but they had a recir pump, with check on cold inlet. The maintenance man said it was a bad check, but I wasn't convinced. 

They had hot water in all toilets and all the faucets had hot on cold side. I found a mixing valve bad underneath one of their hands free Sloan faucets. The solenoid was hung up and the hot was bleeding over there...

A shower valve in theory is a mixing valve, if the cartridge is bad then yes it will reek havoc over the whole house....


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## voltatab (Jan 2, 2010)

How do I go about checking for bad shower cartridges, remove the trim and feel for hot water on the cold inlet?
Or listen to the sound of water passing through at each valve when running the problem fixtures?


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## IBEPLUMBING (Jun 6, 2011)

I agree. bad or defective could be easiest. Checkvalve should be on cold line closest to tee tie in of circ line into cold in of hwh 1st tank not storage or second. ps Dont forget the expansion tank. per code the pump should have iso valves. shut the iso valve and then check.hows the dip tube? no white particles in the hot water right? next check and/or replace the carrtidges of all single handle faucets. they will cross over when bad. that set up is similar to a solar set up exactly except 1st tank is also enabled with radiant heat and glycol line tie ins. A recent repipe could be backwards somewhere. Hope it helps. As you know hard to tell without seeing it.


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## Plumberman (Jul 7, 2008)

If the shower valve has stops inside the wall you can isolate it and tell right then if it's bad. The water won't be luke warm on the other faucets almost instantly. 

If they don't have stops, I have heard of people using a stethoscope to listen while the handles to shower valve are off, they say you can hear water passing threw the valve if it's mixing...


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## plumb nutz (Jan 28, 2011)

voltatab said:


> So re plumb it so cold water is actually water for both WH cold inlets and combine the two WH hot outlets into the hot water to the house, correct? So now both get the same amount of use instead of one getting to do all the work. And then tee the return into both drains , Yeah?
> 
> As far as a bad cartridge, it seems an odd choice due to the timing of it all
> Also, because I've yet to personally run into it, how can a bad cartridge really flows that much water through it and wreak so much havoc? do you have an example of how this happens?


Parallel is the only way to pipe in two heaters, and yes to what you already said.

Cartridges are tricky but I usually check what gets used the most and what gets used the least.
I have found a few bad positemps leaking in a forgotten bathroom...
Sometimes the crossover only occurs at one place, start there, work backwards


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## voltatab (Jan 2, 2010)

Well she rescheduled for next week. 

My thoughts are this
Everything was fine before I changed the water heater. Even If the dip tube was bad, it's still getting hot water fed into it by the other heater, and youd have issues throughout the home, not just parts(i would guess) also, I had an instant change in problems once I flipped on the Recirc, which would point to the recircs check valves. Now she says that even with it on it started doing it again 3 days later. 
I'm thinking the Recirc has now died possibly? It's a grunfos pump. 1/2" inlet. 
I'll see soon enough, but I will be putting my leak detector on those valves to check for crossover and I'm gonna Repipe it correctly


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## SlickRick (Sep 3, 2009)

You broke my recirc. pump.


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## voltatab (Jan 2, 2010)

I did? Oops


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## HOMER (Jun 5, 2011)

non pressure balanced Moen cartridges are known to cross connect while in the off position.
test by turning off hot wtr.
run hot only in moen shower,kitchen,basin
if cross connection occurs,you'll get water coming out(with valve turned to full hot)

not sure if that is your situation.
also had a washing machine cross connect at a defective solenoid valve,but thats rare.


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## Redwood (Sep 8, 2008)

HOMER said:


> also had a washing machine cross connect at a defective solenoid valve,but thats rare.


Nope! The water will go into the washer drum without a crossover...

However, Symmons style washing machine valves can crossover when they fail...


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## HOMER (Jun 5, 2011)

it may not have been a defective solenoid valve,Im no washer repairman,
but turning off this coin op washer in the laundry room corrected the cross connection.


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## Widdershins (Feb 5, 2011)

HOMER said:


> it may not have been a defective solenoid valve,Im no washer repairman,
> but turning off this coin op washer in the laundry room corrected the cross connection.


 Sounds like the solenoid was plugged with debris, not defective.


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## voltatab (Jan 2, 2010)

Finally got it. 

Price pfister shower cartridge was causing my problems. Is there any way that I could have cause that while I replaced their WH? (that's when it started )
They are repeat customers and are struggling to accept that it was just a coincidence.


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## SlickRick (Sep 3, 2009)

If you used that faucet to bleed the air out, it is possible to get debris in the cartridge. Did you cause it? no, It just happens sometimes.

We had a call behind a handyhack that changed a wh, the kitchen faucet would not let flow through. He used the kitchen to bleed air and trashed the diverter.


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