Ask Me Help Desk - Heat traps and recirc. Pumps on water heaters

Heat traps and recirc. Pumps on water heaters

Just replaced our water heater and have been getting low hot water times at shower heads (plenty of time at sink faucets).

If I have a recirculating pump, should there be a heat trap in the cold water supply line ? It appears from the piping method in our home that the recirculating pump supply line dumps into the cold water supply line before entering the tank. If a heat trap (our is a new whirlpool gas water heater with a black rubber washer type diaphram heat trap.

There is no heat trap in the hot water supply side

Question again is should it be removed if you have a recirc. Pump?

Do you have check valves on the recirculation line and on the cold water input to the water heater line?

Quote:

Originally Posted by hkstroud

Do you have check valves on the recirculation line and on the cold water input to the water heater line?

Thanks for the quick reply. Doesn't look like there is a check valve. I do have a gate valve in the line from the pump back into the line that feeds the cold water into the tank, and there is a gate valve between that line junction and the cold water inlet nipple of the tank.

I did go look at the old tank and there isn't a rubber heat trap (and the metal nipples didn't have a ball bearing type heat trap either) . The replaced tank was over 15 years old so that may explain why.

I re attached everything the way it was originally except for installing braided stainless steel hot and cold hoses for an easier replacement down the road for myself or the next home owner.

When hot water is turned on at a faucet or shower head, the pump and its up and down stream supply lines become cold to the touch. I just felt the cold water supply line and it's hot as well. I'm guessing that's normal as hot water is being mixed with the cold back into the tank. That was why I asked about the heat trap. Seems almost like it shouldn't be there in a recirc. Pump set up.

Sorry if I'm rambling. I'm trying to give an accurate and complete list of all the symptoms. Must be the architect in me.

Wondering ? Can you download pictures into this forum? That might clear a lot of the confusion.

1 Attachment(s)

Yes you can upload pic to this site.

You need a check valve on the recirculation line just before it connect to the main cold water input line to keep the cold water from going through the recirculation line when you open a faucet. You need a check valve on the main cold water line just before the connection of the recirculation line to prevent hot water from going up the main cold water input line.

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Quote:

Originally Posted by hkstroud

Yes you can upload pic to this site.

You need a check valve on the recirculation line just before it connect to the main cold water input line to keep the cold water from going through the recirculation line when you open a faucet. You need a check valve on the main cold water line just before the connection of the recirculation line to prevent hot water from going up the main cold water input line.

=========================================

How do I add pictures and other file types to my post?

A. "Attach" files (including pictures) from your computer. This method puts the attached file below the text of the post.

Click on an Ask or Answer button to ask or answer a question
Compose your question or answer in the window.
Under the window where you composed your question or answer is a section called Additional Options.
Click on the Manage Attachments button: a pop-up dialog will open. NOTE: The Manage Attachments dialog lists the maximum sizes of the various types of files that may be attached.
Click the Browse button to navigate to the image on your computer and double click the file on your computer: this will return you to the dialog window.
Click the Upload button.
Click the link to close the dialog window OR repeat numbers 5 & 6 to attach another image.

B. "Embed" image(s) from the internet. This method inserts an image wherever you wish within the text of your post.

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Thanks Harold,

http://i175.photobucket.com/albums/w...DSC_0125-1.jpg

So here's the current set up replaced exactly as the original install. The supply line from the pump running to the right connects into the cold water supply. The yellow gate valve handle is blocking the view of the actual connection. The hot supply is the line on the left (closest in the picture) and the cold supply is in the right (background behind the flue riser). The hose bib in the upper right hand corner stops water flow to the water heater.

http://i175.photobucket.com/albums/w...0/DSC_0128.jpg

http://i175.photobucket.com/albums/w...DSC_0126-1.jpg

2 Attachment(s)

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Quote:

Originally Posted by hkstroud

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Hey Harold. The connection in question is just another gate valve in line before hot water comes back to the recirc. Pump from the loop .

Then you need a check valve on the recirculation line to prevent cold water from the main supply entering the recirculation line when you open a faucet.

To verify, close stop valve on recir line and see how long your shower has hot water.

Quote:

Originally Posted by hkstroud

Then you need a check valve on the recirculation line to prevent cold water from the main supply entering the recirculation line when you open a faucet.

To verify, close stop valve on recir line and see how long your shower has hot water.

Thanks Harold,

I'll try that this evening. Any thoughts or comments about my thought on removing the heat trap from the cold water supply line into the tank?

Don't see what you refer to as heat trap. Is it internal to water heater or is it part of cold water braided supply? Not a factor though, heat traps theoretically stop or reduce heat loss back up piping.
My opinion, just something to have to periodically have to replace. Certainly don't want one on the hot water out line. Would be totally useless because you are constantly pumping hot water through the line.

Quote:

Originally Posted by hkstroud

Don't see what you refer to as heat trap. Is it internal to water heater or is it part of cold water braided supply? Not a factor though, heat traps theoretically stop or reduce heat loss back up piping.
My opinion, just something to have to periodically have to replace. Certainly don't want one on the hot water out line. Would be totally useless because you are constantly pumping hot water through the line.

The heat trap on this water heater is basically a black rubber washer located between the dip tube and the nipple running into the cold water supply side of the tank. It has a cross shaped slotted penetration to allow water to be forced into the tank, but the slot closes when water isn't being supplied to the tank. Some of these newer heat traps are nipples with a ball bearing that works in a similar fashion.

Doesn't seem necessary on this tank as we're constantly feeding hot water back into the cold water supply into the tank.

OK, agree but shouldn't hurt any thing. You said you have recirculation pump on timer. Flow will only be when pump is running. Confidant that you will find you have plenty of hot water when you close stop valve on recirculation line. Which will confirm that a check valve is needed on recirculation line. You probably have plenty of hot water when pump is running also.

Quote:

Originally Posted by hkstroud

OK, agree but shouldn't hurt any thing. You said you have recirculation pump on timer. Flow will only be when pump is running. Confidant that you will find you have plenty of hot water when you close stop valve on recirculation line. Which will confirm that a check valve is needed on recirculation line. You probably have plenty of hot water when pump is running also.

No that's what's weird. The amount of hot water at the shower wasn't affected by the pump running or not running. It literally runs out after about 5 minutes. The old water heater allowed for pretty long showers 10-20 minutes if you needed the soak.

What is also weird is that the pump and the lines feeding it get pretty cold once you start running a shower head. Pump running or not.

Plumbing is a strange animal to me.

That sounds like pump is shot. When you open faucet water flows not only from the water heater but also from the cold water input pipe. Why would pump go at this particular time? Murphy's law.

Quote:

Originally Posted by hkstroud

That sounds like pump is shot. When you open faucet water flows not only from the water heater but also from the cold water input pipe. Why would pump go at this particular time? Murphy's law.

Like when you change the anti freeze in a car and the water pump invariably dies at the same time??