Latest Discussions : Plumbing


07:26AM | 02/18/05
Member Since: 01/28/05
4 lifetime posts
Thanks for taking this message.

We have two problems.


new house ( 11 months ) 2 50 gallon heaters in series. Water is warm, not hot when filling a jacuzzi tub. ( about 50 gallons )

leaving the water off for about 10 minutes and we get very hot water out of the same spicket. We have for thermostats on the two water heaters. all are a little past half way. no temperature gage, just labeled ABC. All set the same, all just a little warmer than the B setting.

Second question. My first attempt to fix this was to crank up all 4 thermostats. not all the way, but apparently close enough. after 20 minutes we blew a joint and had a mess. pvc line is rated to 180 .

how high should i be able to turn those things up?

I'm guessing I don't need to turn all up? or do I.

Thanks in advance



04:19PM | 02/18/05
You can't use PVC on hot lines. They won't stand up. You can use CPVC but not connected directly to the heater. You can use a thermometer at a faucet outlet to set your water temperature around 120 degrees.

Jim D

08:44AM | 02/22/05
Member Since: 01/06/01
342 lifetime posts
Sonnydebbie - hi, assuming you have electric water heaters, you should check the heater elements in the second water heater (the one whose hot water output flows to the faucets in the house). If the heaters are truly in series, it sounds like the second heater isn't keeping the water in it hot. You said you drain off that water into your jacuzzi tub, and you get very hot water about 10 minutes later...that very hot water is coming from your first heater (the one connected to the incoming water lines) which has refilled the second heater.

You can use an ohmmeter/digital multi-meter to check the elements. With the electricity shut off, set the meter to measure ohms and place the leads of the meter on the ends of the heater element. You should get a small amount of resistance...maybe around 100 ohms or so. If you get a very high resistance or read an open, then your element's bad.

When replacing the element, be sure the water heater's drained before removing it and be sure it's full of water again before applying electricity back to it. Otherwise, you'll burn out the new element.

You should be able to find the manuals for your water heaters to determine how high to set the thermostats. Check the manufacturer's website or see if similar brands are sold at your local big box stores and plumbing supply houses...I've seen this question asked before and I believe the top thermostat is set a little hotter than the bottom one. The bottom thermostat runs its heating element to heat the new (cold) water in the tank and the top thermostat runs its heating element to maintain the water at the desired temperature.

I hope this helps some - regards! Jim D/West Point, VA


12:41PM | 02/22/05
Member Since: 01/28/05
4 lifetime posts
Thanks Jim

Had the plumer here today and he found two thermostats to be arching? replaced both. they were the bottom thermostats in both w. heaters. it seems to be working...

if not we will try the elements next.

thank you for your help.


Jim D

11:53PM | 02/22/05
Member Since: 01/06/01
342 lifetime posts
Sonnydebbie - hi, I'll bet the plumber checked the elements as he did his troubleshooting. If all seems to be working well for now, then you're probably good to go! Also, did you have the plumber redo the piping? (LonnythePlumber's advice on the piping in his reply to your original post...)

I had a whirlpool tub in my last house (rental house) that I repaired for my landlord. We only had 1 hot water heater serving the entire house...if I ever put a whilrpool tub in, I'd planned to provide the tub with its own hot water heater. I'm not sure I'd install 2 of them in series as you have, but it's an alternative solution.

The other option, which I'm not sure is available, is to do like is done for Jacuzzi tubs and install an in-line heater with the pump mechanism. (I had one of those to repair for the landlord as well...but it was nice to use those items after they were working fine!) Regards! Jim D/West Point, VA


06:02PM | 08/10/18
if a elec. water heater is made to use 5500 W element . Can you use a 4500 W element ?

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