What is the best location for a Hot Water Recirculating Pump?

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Old 01-13-15, 01:30 PM
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What is the best location for a Hot Water Recirculating Pump?

Hi,

I currently have a recirculating pump installed with my Lochinvar (boiler) with a Squire (indirect hot water tank). I was having low hot water pressure issues and my plumber discovered that the check valve, installed where the recirc pump was, had nearly closed up due to corrosion or something.. It has only been there about 2 years and seemed to be a problem from the initial install.

The placement of the pump sends the returned hot water into the cold water input on the Squire tank (near the bottom if I recall). My current plumber has removed the check valve and isolated the recirculating pump so that I can determine if it's needed or not. It does appear one is needed, since with it turned off, it takes a long time to get hot water to certain areas of the house. But, either way, the water pressure is much better overall.

My plumber has mentioned that it would be better to have the pump location moved so that the return was not going into the cold water input, rather into where the relief valve is (with a Tee), or maybe the top of the tank. He's been a plumber for a very long time and I respect his recommendations, but I know he is not super familiar with this type of system. Just want to see if anyone has any input as to the best way to handle this?

Thanks in advance!
~Ed
 

Last edited by akegb3; 01-13-15 at 01:55 PM.
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Old 01-13-15, 03:46 PM
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Hi Ed.....

Tell your plumber to follow the diagram on any of the pages here. 7,8,9...etc

http://www.lochinvar.com/_linefiles/...%20Rev%20N.pdf

If this is how its piped now then there is no reason to change it as it is correct...


You may have sediment issues and the indirect needs to be flushed more often. If you have the pump move to feed high at the relief valve, then you will be mixing cool water at the top of the heater, and it may affect the temps when using hot water...


Did the plumber install the drain valve as shown in the diagram? Its after the check valve as shown?


Let us know...
 
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Old 01-13-15, 04:40 PM
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Hi,

I'll attach a photo which was taken before the circulating pump was installed (only pic available at the moment), but I've drawn it in as to how it was before the check valve was removed. Question I have is, how do I flush it if I know it's going to cause a problem?

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Old 01-13-15, 06:37 PM
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Check valve in wrong spot... Should be after pump but before the tee,,,

Flush from drain on bottom of heater twice a year. Turn off cold water to heater and drain sediment out...

You opened the link in the post below?
 
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Old 01-13-15, 06:45 PM
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It has only been there about 2 years and seemed to be a problem from the initial install.
Probably getting flow back through the loop and hot/cold/hot cold issues.. Or like you run out of hot water and can never get it real hot right?
 
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Old 01-13-15, 07:56 PM
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Yes, I did look at the link and thought the valve was in the wrong place and you've confirmed that. Thanks for the flush tip!
 
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Old 01-13-15, 08:00 PM
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Without the pump altogether, certain parts of the house can never get real hot water. With the pump now without a check valve, it does get hot everywhere, but not sure how good that is working overall. I will definitely show my plumber the diagram you've pointed out. Also, would it be better to be down nearer the intact on the water tank like the diagram shows? Thank you very much for the quick and awesome help! -Ed-
 
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Old 01-13-15, 09:49 PM
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Also, would it be better to be down nearer the intact on the water tank like the diagram shows?
No not at all...

Is the pump running 24/7? Or is the pump hooked to an aquastat of some kind?


With the pump now without a check valve, it does get hot everywhere, but not sure how good that is working overall.
May be hot for a few moments, but without a check valve I dont know how its working right..

Whats the make and model of pump?

Also what kind of check valve? If a swing check then they must be installed in a horizontal position. Spring checks can be installed in any position... They are directional too...
 
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Old 01-14-15, 10:35 AM
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Is the pump running 24/7? Or is the pump hooked to an aquastat of some kind?
Yes, it's running 24/7, which I'm not that wild about. I'll mention an aquastat to my plumber.

Whats the make and model of pump?
The pump is a Taco, Model 006-B4

I'm not sure what kind of check valve it is, attaching a picture of it and a picture of the pump and possibly another check valve on the other side of the pump...which I'm guessing is 'not' needed.

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Thanks again...you are very helpful!!
 
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Old 01-14-15, 03:44 PM
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Well if the pump is hooked back up and you have the check valve on the back side of pump that should be fine... All should work..

The pump running 24/7 will cause the indirect to fire the boiler more often and waste fuel.. An aquastats is usually installed and set to 90f. This will kick on the pump only when the temp of the water in the return falls below that..

So how is the hot water now working?

One other issue I see is when certain shower valves fail you can have a mixing issue.. These specifically would be thermostatic shower valves. Do you have any of these? To know you would have two seperate handles in the shower. One to turn on the water and one to adjust temp.

And come to think of it, I am not sure recirc lines work with this type of valves...

Let us know...
 
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Old 01-14-15, 04:32 PM
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Yes, the pump is hooked up as shown.. to the right is the tee into the cold water supply going down into the tank. So, there were two check valves installed originally, the one you see now on the back side and the one that was vertical in the cold supply.

I will look into having an aquastat installed for sure. I noticed I had to push the temp control in the shower towards hot more than usual, and the cold water tap in the sink was pretty warm to start, but did get cold in maybe 15-20 seconds. So, this one shower has a very new Delta shower system where the on/off handle has a temperature control knob on the inside of the handle. I just found it online, it's a TempAssure Thermostatic control system.

Also, could you identify the brand of the check valve I posted?

Thanks again!
Ed
 

Last edited by akegb3; 01-14-15 at 04:56 PM.
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Old 01-14-15, 04:51 PM
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So, this one shower has a very new Delta shower system where the on/off handle has a temperature control knob on the inside of the handle.
That could be your issue but did you always have this type of shower? Im not sure that the all in one valve as you have is an issue...


Also, could you identify the brand of the check valve I posted?
Its a spring check.. Dont know brand but they are resistant to corrosion..

Also have you checked the mixer valve above the heater for proper operation and temperature settings> These also get calcium build up. The temp handle needs to be moved periodically... Try turning it up and down...

Last possible the boiler is not heating the indirect properly.. Bad t stat at the indirect??? Whats the temp of the indirect set for?

It would be niice to have a valve at the recirc pump. Turn the pump off, shut the valve off at the pump to isolate it, and run the system normally as a test...

These are all the things your plumber should be doing for you...

Dont know his skills but possibly you may need to call in someone else.....
 
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Old 01-14-15, 05:15 PM
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The shower with the all in one valve is about 12-18 months old...part of our new edition. I really don't think it's part of the problem.

Also have you checked the mixer valve
I'm thinking about getting rid of the mixer valve altogether and one other one we have upstairs in the older part of the house, just to rule out any issues with them. The one you see was installed by me...so could be a potential problem;-)

The plumber I'm using now was not the plumber who installed the system-I've run them off already. He has actually isolated the recirc pump electrically already, and added some other helpful isolation valves elsewhere, and did mention adding one as you suggest, so I think he'll be okay;-)
 
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Old 01-14-15, 05:27 PM
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OK well. I hope I helped you out... Keep us updated as you modify things..
 
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Old 01-14-15, 05:42 PM
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Yes, you've helped a lot and it's very much appreciated. My plumber returns Saturday, so will update next week!
 
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Old 01-14-15, 06:15 PM
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Im not a pump specialist but maybe the check valve needs to be on the pump side and not the suction side as you have it...

Its just every drawing you look at its on the other side of the pump... Possibly the suction side cant open the check valve and recirc the water?

Maybe others will chime in...
 
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Old 01-14-15, 06:30 PM
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The hot water is definitely recirculating since the cold water pipe it's going into now gets hot, above where the other check valve used to be. Seems odd they had two to begin with though!
 
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Old 01-14-15, 06:36 PM
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If you open a cold faucet does hot water come out??

I'm thinking about getting rid of the mixer valve altogether and one other one we have upstairs in the older part of the house,
I think this could also be the issue. Whats it there for? A tub???

Possible hot was going back into the cold line, why another check was installed...

When you have issues like you do its usually a place where h/c can mix..

The one over the water heater is probably fine.. The other may be the cause...Most likely...
 
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Old 01-14-15, 08:55 PM
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Just tested all sinks, showers and tub. Cold sides were mostly cold off the bat with one kinda getting warm before getting really cold. All the hots were good, but a couple took longer than others. Water pressure is great everywhere. Perhaps after a long night the hot mixes more with cold which explains why the sink in the master bath this morning seemed warm.

The other mixing valve feeds two toilets upstairs. Been there since 1993.

That other check valve was installed at the same time as the pump. There were three or four "plumbers" here scratching their heads deciding how to do it
 
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Old 01-20-15, 10:21 AM
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Well, my plumber fixed some other issues, but didn't address this one except to say that he recommended another check valve right back in the same place as the one he removed. I showed him the diagram from the Squire manual more than once and it was like I was talking to a brick wall. I also mentioned a aquastat and he thought that was a good idea. I'm thinking a different plumber is now in order. Although the water pressure and everything is working much better, I'd like the aquastat and check valves in the correct location... any recommendation on the type of aquastat?
 
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Old 01-20-15, 11:20 AM
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I found the following instruction manual for Lochinvar Squire and I'm a bit confused as to how it shows the installation of the hot water recirculating line and input back to the tank. It doesn't appear to go into the cold water input as other diagrams have shown, and it appears to only circulate from the top of the tank to the bottom...

http://www.lochinvar.ltd.uk/sites/de...r_Heater_0.pdf
 
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Old 01-20-15, 04:06 PM
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and it appears to only circulate from the top of the tank to the bottom...
Its a loop just like you have... Going into the cold line should have no affect unless you have another mixing point... I say its that other mixer maybe...

The pump is pumping back into the cold line through the other mixer it would seem to me...

The other mixing valve feeds two toilets upstairs. Been there since 1993.
Probably dont work and it not needed IMO... Has it been serviced since 1993?

any recommendation on the type of aquastat?
I would say a aquastat and set to like 90f or so... Like this...

L6006C1018 - Honeywell L6006C1018 - High or Low Limit & Circulator Strap-On Aquastat, 65-200F range, 5-30F Adj Differential
 
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Old 01-20-15, 04:17 PM
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The upstairs mixing valve has not been serviced since 1993... I will check it and replace or discard it.

Thanks for the aquastat recommendation, I think my electrician son-in-law and I can get that installed. Can it be strapped to the pex or does it need to be copper pipe?

Thanks again!
 
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Old 01-21-15, 10:31 AM
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FYI... checked the upstairs mixing valve and it does appear to be working properly. Cold water input is cold and hot is hot...mixed line gets warm when toilet is flushed. Did not detect any cold mixing back into the hot line.
 
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