Hot Water Recirculating Line

jdupre

I would like to install a recirulating pump (a Metlund S-70T) in an existing recirculating line. This line has not been used in at least 30 years. It has been plugged close to the water heater. I took the plug out and ran some hot water through it and it is working fine.

My question is: how do I hook the return line into the water heater, a standard 40-gallon GE tank-type heater that runs on natural gas? The plumbing diagram shows it going into the bottom of the heater. The only place I can see to hook into the bottom of the heater is where the tank drain valve is. I suspect I should remove that valve and run the recirculating return line in there. Is that correct? Also will I need a one-way valve in the line to prevent water from flowing from the tank back into the recirculating line?

Thanks for any help!

NateHanson

Don't you tee the return into the Cold water feed right before it enters the heater?

RippySkippy

Don't remove the valve at the bottom of the tank...you use that to flush the water heater each year...you do flush you tank don't you? If not...do it now.

I'd plumb it in on the supply side of the water heater, where ever it's convenient. From what I read, that unit has a built in check valve....

cjett

Have a look at Grundfos pumps. It is easy to install and works great. As far as using the bottom of the tank for the return, it will keep the tank a lot cleaner running water back with the pump working every day than flushing water once a year, think about it.

http://www.grundfos.com/Web/HomeUs.n...ag/PAVA-53MKRN

RippySkippy

Re-circulating the crud in a tank does not replace the need to drain it.

cjett

That's probably true too. You should put a valve in the line to be able to drain it. But if it is an old heater that has not been drained in years, it may not do much, either. That grundfos pump does work great if you have to wait for hot water at the far ends of the line. The one for new construction is the one you probably want to use if there is already an existing return line.

Marlin

You don't have to do it every year. Do it once after a year, if you get a lot of stuff then yes you have to do it often. If you don't get much every few years is fine.
And if you had to go into the bottom you would just use a nipple with a tee on it so you could retain the drain.

jdupre

Thanks, everybody, for the helpful information. I did insert a tee betweein the drain valve and the tank and installed the pump there.

It did not work at all! The pump sounded very labored when activated, would run for about 4 minutes and then stop. I activated it 3 times in a row with no trace of hot water anywhere down the line. I'm almost sure there was a one-way valve behind the tank drain valve which prevented water from being pumped into the tank.

Anyway, I removed the pump and installed it between the hot and cold lines to a bathtub at the far end of the run and it works great. I could probably install it at the water heater using the dedicated line and connect it into the cold water supply line above the heater but I'll probably leave it where it is since it's working there.

Thanks again for all the help!

cjett

Which pump did you use? Glad it is working good for you. If you have your hot water heater on one end of the house and the master bath on the other end like mine, it sure makes it nice to not have to wait for the water to get hot.

rcatty

I have been in this house for 10 years. I am on a well, and have two hot water tanks set up to work in parallel. I am getting a sediment discharge in my hot water, only from my upstairs faucets and showers. The hot water tanks were extremly dirty and it took several drainings and flushings to clear most of the debris. Apparently, I have a recirculating system, as I notice copper pipes entering the drain valves at the bottom of the tank. I see no pumps anywhere on the system, nor have I heard anything "pumping" since I have been in this house. The recirculating pipes branch off in two opposite directions to either side of the house. The recirculating system seems to work fairly well on one side of the house (although lately nowhere as good as in the past). I see no positive results on the other side of the house, where I traced that circulating line. Indeed that side of the house, be it upstairs or downstairs, never showed any benefits of instant hot water.

The recirculating lines are very hot for about 10-15 feet as they join the bottom of the hot water tanks. I see no check valve anywhere. I suspect I am getting backflow up the recirculating pipes with hot water off the bottom of the tanks. Is it possible that sediment off the bottom of the tank could be pushed up to my second floor faucets via the recirculating lines causing the sediment discharge? The upstairs faucets in the master bathroom with the fastest hot water, discharge the most debris. However, in a second upstairs bathroom there is discharge from one sink faucet and the bathtub faucet (the instant hot water, if installed in both faucets works poorly, if at all). Interestingly, I see no discharge from the second sink faucet in that bathroom. A third bathroom upstairs discharges in a similar fashion to this latter bathroom, but the instant hot water appears to work (this is on the same side of the house as the master bathroom, and must feed off the same branch of that end of the recirculator. The other bathroom, that works poorly, if at all, is at the far end of the house and has a long (25-50 foot) horizontal run to the water heater. I don't see how that could work properly on a gravity based system ? In summary, how do I stop this sediment discharge, and secondarily, how do I fix my recirculating system on the other side of the house? Thank you