Water takes 30-40 secs for bathroom showers to get hot after new Hot Water heater

[lesjanes]

Problem: Water takes 30-40 secs for bathroom showers to get hot after new Hot Water heater installed. Previous Hot Water tank delivered in 3-5 secs.

House: Ranch about 3500 Sq ft, Family of 4 (just 2 now with kids in college)

Old Setup: 75 gal. AO Smith with recirculating pipe set up (NO PUMP). 35 feet from tank to last faucet. Setting on high.

New Setup: 50 gal Bradfor White, reconnected recirculating pipe set up. Only difference a couple of 90 degree turns in recirculating side to accommodate new tank install. Setting on low.

When I figured out our AO Smith was 28 years old, thought it was time to change before it started leaking. (water was also smelling and more debris in water) I had a plumber replace with a 50 gal tank because I thought another 75 gal was just over kill for a small family in a ranch home.

With the old heater, we got hot water in the far bathroom in less than 5 secs. Now with the new heater it takes 30-40 secs to get hot. Until now, I didn’t understand much about recirculating systems (I didn’t even know my tank was setup that way).

So now that I think that I understand the system a little better, I have a couple of questions: 1) How was my old tank able to deliver hot water so quickly without a Recirculating Pump? 2) How come my new one doesn’t do the same?

Once the hot water gets to the far end of the house, I have no problem with the water temperature. It just takes so long to get hot now.

Does anyone have any ideas or advice?


Thanks,
Les

 

[Reach4]

So now that I think that I understand the system a little better, I have a couple of questions: 1) How was my old tank able to deliver hot water so quickly without a Recirculating Pump? 2) How come my new one doesn’t do the same?

Was the recirculation inlet vs output maybe larger on the previous tank?

Is the water tank specifically designed for gravity recirculation, or are you maybe using the drain cock on the side of the tank. The heat traps as part of the new install could be messing you up. https://terrylove.com/forums/index.php?threads/gravity-recirc-stopped-working.57926/

 

[Sponsor]

 

[lesjanes]

Reach4, thanks for the reply and the link. Inlets / Outlets are the same. I thought of that as well. I am using the drain cock on the side of the tank, just like the AO Smith was set up.

I don't the new tank is specifically set up for gravity recirculation. You are starting to make me wonder if the new tank's design is part of my problem. I can fix minor plumbing problems...is a heat trap easy to locate and remove?

Thanks for your help. the Link you provided was also helpful.

Les

 

[Jadnashua]

Many new WH come with heat traps. They typically are installed on both the hot and cold supply points (and are not interchangeable!). For gravity recirculation to work, the slope and path of things has to be just right. Adding a couple of elbows may have been enough to disturb the flow, depending on how the piping is now routed. A heat trap could easily have enough resistance to stop convection flow...that is what they were designed to do! IOW, if you have them, you need to remove them for a convection recirculation system to work. A pumped system can overcome that resistance from a heat trap.

 

[Reach4]

I think they are in the top nipples, and the one you care about is the hot side. Maybe you can find documentation specific to your water heater.

If you have flex lines for your install, it will be easier than if you have copper tubing soldered into place. I don't know if you will be able to lift out an insert, or what. Somebody who has done this may tell you what you can expect.


http://www.bradfordwhite.com/heat-trap-fitting-vertical-or-horizontal-style

http://www.bradfordwhite.com/important-announcments-18

 

[hj]

A gravity circulation system is a very delicate thing. Adding those elbows, and maybe adding or removing a check valve could have disrupted the flow. How about a picture of how the circulation line is connected. Take if from far enough away so we can see more of the piping than just the actual heater connection.

 

[lesjanes]

A gravity circulation system is a very delicate thing. Adding those elbows, and maybe adding or removing a check valve could have disrupted the flow. How about a picture of how the circulation line is connected. Take if from far enough away so we can see more of the piping than just the actual heater connection.

Thanks all for your input. In the below picture, the section from drain cock to first elbow is 4 1/2 feet, the horizontal line going left to next elbow is 20", the up for 12" to next elbow then parallel for another 20" (behind duct work).

Ok, here is the bizarre part, when I run the kitchen water (middle of house) it never gets hot, just warm, unless I open the the laundry tub faucet downstairs full blast. Then that water is hot and upstairs sink is hot. When I shut off laundry faucet, the upstairs sink go back to just warm again!!

It almost seems like water is being drawn from both the recirculating side and hot water side of the tank. The cooler bottom tank water mixing with the hot water from the other direction. Is that possible? If so, my recirculating system is pointless and I should install a shut off valve on the recirculating side.

Thanks again for all of your suggestions.

 

[lesjanes]

I think they are in the top nipples, and the one you care about is the hot side. Maybe you can find documentation specific to your water heater.

If you have flex lines for your install, it will be easier than if you have copper tubing soldered into place. I don't know if you will be able to lift out an insert, or what. Somebody who has done this may tell you what you can expect.


http://www.bradfordwhite.com/heat-trap-fitting-vertical-or-horizontal-style

Ok, if I understand the article correctly, if I remove the heat trap fitting, I risk that the "ball" on the hot water side flows into my house plumbing.

Is that correct?

 

[Reach4]

The way I read it, there is some cap that could be removed that would allow the ball to be removed. But you should not remove that retaining cap without also removing the ball.

 

[Smooky]

The article about the ball might be an old article. One of those links says: “The new heat trap design incorporates a small disc” You may be able to disconnect the hot side of the hot water outlet on the heater and pull out the heat trap insert. If that is not the case you may have to remove the ball.

 

[Master Plumber Mark]

The problem is in the top of the water heater...
Bradford white sends out their heaters with little flapper--check devices
inserted on both the hot and cold nipples on the water heater...
they act like little plastic check valves to keep the heat inside the heater which is
NOT what you want to happen... they certainly stop the natrual flow that you are wanting to happen

ask your plumber if he left them inserted inside the dialectric nipples....

We always take them out with a pair of needle nose pliers and throw them
away....

 

[lesjanes]

The problem is in the top of the water heater...
Bradford white sends out their heaters with little flapper--check devices
inserted on both the hot and cold nipples on the water heater...
they act like little plastic check valves to keep the heat inside the heater which is
NOT what you want to happen... they certainly stop the natrual flow that you are wanting to happen

ask your plumber if he left them inserted inside the dialectric nipples....

We always take them out with a pair of needle nose pliers and throw them
away....

Thanks for the tips.I am waiting for the plumber to come back. We will strategize then.
Thanks,!

 

[Reach4]

If it is not making noise, I think it would be good to leave the cold side heat trap in place.

 

[hj]

The problem appears to be that there is NO CHECK valve in the circulation line at the heater. THerefore, cold water is flowing through that line DIRECTLY to the shower valve, UNLESS the other faucet is opened and there is enough flow that the hot water gets to the tub/shower first. But as soon as that extra flow turns off the circulation line again becomes the main feed, because it is more direct than the hot water line with its myriad of turns and fittings.

 

[Master Plumber Mark]

The problem appears to be that there is NO CHECK valve in the circulation line at the heater. THerefore, cold water is flowing through that line DIRECTLY to the shower valve, UNLESS the other faucet is opened and there is enough flow that the hot water gets to the tub/shower first. But as soon as that extra flow turns off the circulation line again becomes the main feed, because it is more direct than the hot water line with its myriad of turns and fittings.

If you are attempting to make this a passive thing, , you cannot have any check valves in the system or even a stop that could restrict
the flow of the Passive MOJO.......(plumbing technical term )


Just take off the nipples on the heater and remove those plastic heat traps and it should work fine
the Passive MOJO will return to its previous state.............

 

[hj]

quote; you cannot have any check valves in the system

you MUST have a check valve in the system, but it is either installed at a slight angle so the gate hangs partially open when there is no attempt at backflow, OR you drill a 1/4" hole in the gate to allow the circulation.

 

[lesjanes]

quote; you cannot have any check valves in the system

you MUST have a check valve in the system, but it is either installed at a slight angle so the gate hangs partially open when there is no attempt at backflow, OR you drill a 1/4" hole in the gate to allow the circulation.

The previous set up did not have a check valve. But it was a much larger tank and the heat setting was high.

I have the same suspicion that you do in that I need a check valve AND I need to remove that damn heat trap. One of the symptoms is that the kitchen faucet never gets hot, only warm UNLESS I open a large faucet. Then it is hot all over. At least until I close that large faucet.

 

[lesjanes]

The previous set up did not have a check valve. But it was a much larger tank and the heat setting was high.

I have the same suspicion that you do in that I need a check valve AND I need to remove that damn heat trap. One of the symptoms is that the kitchen faucet never gets hot, only warm UNLESS I open a large faucet. Then it is hot all over. At least until I close that large faucet.

One more question, I don't understand the " installed at a slight angle so the gate hangs partially open " part. How do I insure it is at a slight angle? I was planning on having the plumber install the check valve on the long vertical section just before the recirc section enter the tank.

 

[hj]

It MUST be a "swing check" which has a flap on an angle, and they are all different, but it has to be on such an angle that the flap is partially open, UNTIL you open a faucet and the backflow closes it. It also cannot be in a "vertical" line otherwise it would ALWAYS be open and you might as well not install it. The system could NOT work without a check valve so it must have been there somewhere and it was removed. The flow checks are probably a nonissue. One question, WHAT is that long pipe going over the pan and out of the picture to the lower right hand corner?

 

[lesjanes]

It MUST be a "swing check" which has a flap on an angle, and they are all different, but it has to be on such an angle that the flap is partially open, UNTIL you open a faucet and the backflow closes it. It also cannot be in a "vertical" line otherwise it would ALWAYS be open and you might as well not install it. The system could NOT work without a check valve so it must have been there somewhere and it was removed. The flow checks are probably a nonissue. One question, WHAT is that long pipe going over the pan and out of the picture to the lower right hand corner?

Long pipe...it is just the hose. Looks straight at that point. regarding previous setup....there was no check valve. I was there when he removed the old heater.