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fijimertz 08-16-2011 06:37 AM

Irrigation system impacting hot water temp?
I have been tracking an issue we are having with our hot water temp in the morning (showers). I have been testing the hot temp in a sink with the cold supply turned off.

On days that my front irrigation runs the temp seems to drop into the upper 90s which makes for a warm shower. By mid day the temp is up around 115. On days my irrigation does not run, the morning temp is 115+ and holds through the day. I thought of the simple 'they connected my irrigation to my hot water', but the tank is not empty, nor is it trying to heat the water after the irrigation runs, which I would imagine it would if it was just emptied onto my lawn. Plus the irrigation water is not scalding 115+ coming out.

Any thoughts on why this would happen or tests I can run on the hot water heater? Does general water pressure (which drops with the irrigation running) impact the hot water?

I guess it could be random with the irrigation system running and I actually have a hot water thermostat issue, etc. The hot water heaters is only 5 years old.


oldognewtrick 08-16-2011 06:48 AM

I'd first suggest going to the water heater and putting your hand on the outlet pipe about 3' or so from the tank. Make sure no other usage for the last 15 mins or so, then have someone turn on the irrigation system and see if you can feel a temp change in the pipe. This way you can eliminate the chance of the system being connected to the hot water tank.

Oh, and :welcome: to House Repair Talk!

oldognewtrick 08-16-2011 06:51 AM

And what type of tank is this gas or elec? How many people showering? Time between showers?

fijimertz 08-16-2011 08:04 AM

Thanks, I'll give it a test. It is a gas heater. 2 adults showering, about 20 minutes apart. Temp is consistent between both showers. When the heater is hot, it holds temp for multiple showers well. 75 gallon tank.

Glad to have found this forum!

Redwood 08-16-2011 08:19 AM

Do you have a recirculation system on your hot water?

This question and oldog/newtrick's questions are important...

Snav 08-18-2011 09:14 PM

I remodeled my bathroom last year - before finishing the install of my shower fixtures I had to turn water in the house back on - so I capped the pipes off with the fittings in place, without handles I couldn't tell if they were 'off' or 'on' - and I turned the water on.

Water was then luke-warm in the back bathroom: I capped off my pipes while one of the faucets was on - which was feeding cold water into the warm water line.

I had to turn it off, disconnect it all, cap it, and didn't try to reconnect without the knobs in place so I could see where 'off and on' were. . . problem solved.

(just some new two bits)

fijimertz 09-29-2011 09:33 AM

Again, thank you for the thoughts. After hurricanes, earthquakes and a crown molding project I am back on the hot water heater. I have sine turned off my irrigation system and continue to have intermittent issues, but with no pattern I can determine (after tracking days and temps). I suspect I have a problem with my temperature control on the unit itself. I have no experience with this type of repair, so it may be time to call in the plumber. I'll update with the solution when I get there.

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