water heater question

[blazenut]

I inspected a house today with a high efficiency gas rheem HWH, with a circulation pump on it that was on a timer. It was a very large home, over 4000 sq ft. The radon company that installed the radon monitor unplugged the hot water heater and the pump to plug their unit in to. Two questions: When do you use a circulation pump on a HWH, and why does it have a timer on it? Thanks.

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[waynesoper]

A circulating system on a water heater insures hot water as soon as you open a tap. Usually in large houses where money is unimportant. The timer would start the circulation early in the am when people wake up and shut it down at night. Guess he lost some in the stock market.

So where sid theyt set the monitor. On top of the water heater, next to the vent. Improper placement.

radon test should be in a living area. Not a mechanical room.

[Bill Kibbel]

That's a Grundfos hot water recirculation system. You should have seen thermal by-pass valves at one or more fixtures.

[StevenT]

IMO, controlling the circulator pump with a timer is a poor way of setting up the instant system.

[Richard Moore]

IMO, controlling the circulator pump with a timer is a poor way of setting up the instant system.

May I ask why? I don't see that many hot water circulation systems, but all that I have seen are on timers, some on fancy 7-day programmable ones. Seems like a good idea to me. Why would you need instant hot water in the middle of the night or during the day if no one is usually home? I doubt the pump uses that much power but you are also going to lose some heat during the circulation.

Now...if you live in an area where water is constantly in short supply and a bigger issue than power, I can see setting it up differently.

[StevenT]

IMO, controlling the circulator pump with a timer is a poor way of setting up the instant system.

May I ask why? I don't see that many hot water circulation systems, but all that I have seen are on timers, some on fancy 7-day programmable ones. Seems like a good idea to me. Why would you need instant hot water in the middle of the night or during the day if no one is usually home? I doubt the pump uses that much power but you are also going to lose some heat during the circulation.

Now...if you live in an area where water is constantly in short supply and a bigger issue than power, I can see setting it up differently.

Hi Richard,

There is a better way... at the same cost.

Instead of controlling the pump with a timer, that will operate at pre determined times only, I use an aquastat. It simply bolts onto the pipe, and monitors the temperature of the loop. When the temperature of the loop drops, it turns on the pump. This will give you "instant" hot water anytime, any day. You simply install it, and forget it.

I've put in a few instant systems, some have had different needs, so my mind set is different. I guess if limiting to small residential, where folks basically bathe in the morning and/or the evening, and don't care about the rest of the time, a timer with limited settings will be ok. A 7 day programmable is nice if you can plan that far ahead. Personally, if you asked me what time I will be taking a bath next week, I couldn't answer you. Sometimes I get home at 3PM, sometimes 9PM. Sometimes I awake at 4AM, sometimes at 7AM, etc.

An "instant loop" is pure luxary, not necessity (in most cases). If I am installing a luxary option, I want it to work all the time, not sometimes.

Perhaps my use or the word "poor," was strong. But there are too many reasons why using a timer doen't make sense to me, especially when there is a better way.

[davidlord]

I have a dedicated circulation system with a Grundfos pump that has both a timer and aquastat. No since running it from about 11:00pm to 7:00am.

[StevenT]

I have a dedicated circulation system with a Grundfos pump that has both a timer and aquastat. No since running it from about 11:00pm to 7:00am.

Good set up.

[Les]

Do all you guys have hot water every day? How do you afford it in this economy?

The best solution is just stay out of crawl spaces, avoid cobwebs, drive with the windows down and tap into your neighbor's water heater while they are at work.

[Terence McCann]

That's a Grundfos hot water recirculation system. You should have seen thermal by-pass valves at one or more fixtures.

When I first looked at the picture I thought was the pump was installed in the wrong location.

This link shows the typical installation: http://www.taco-hvac.com/images/DMand_R ... tic_lg.pdf

After reading Bill's reply I went to the Grundfoss web site and found this: http://www.grundfos.com/web/homeaunz.ns ... -11-06.pdf - which talks about installation of a recirc system in an existing dwelling. As Bill said you have to look for the bypass valves that are needed to make this system work.

Learn something new everyday.

[blazenut]

Sorry i didnt reply sooner (on vacation for a couple of days), thank you all for the information.

[msteger]

A circulating system on a water heater insures hot water as soon as you open a tap. Usually in large houses where money is unimportant. The timer would start the circulation early in the am when people wake up and shut it down at night. Guess he lost some in the stock market.

So where sid theyt set the monitor. On top of the water heater, next to the vent. Improper placement.

radon test should be in a living area. Not a mechanical room.

Be careful!

In PA, DEP requires radon testing on the lowest possible living level, not necessarily the lowest currently lived in level as in other states. This means that if the basement floor is concrete, you can stand upright, and you could potentially make this a 'living area' (like a place for children to play) without major work, you make your radon measurements here.

If this room (where the water heater is located) is a relatively small closed-off room from a finished basement, for example, I would take my radon measurements in the finished basement area.