what is typical temp range for a water heater?

what I mean is, what is the difference in temp from when the t-stat is initially satisfied (say 120 deg) and when the flame kicks back on after the hot water has been depleted somewhat?

I have a Bradford-White gas water heater, seems like there can be maybe a 20 deg swing in temp, was wondering if this is normal. I'm not talking about temp dropping after a 1/2 hour shower, but the temp drop of smaller usage before the gas kicks in.

Thanks for the help.


Greg

temp issues...or dip tube problem

Typically if you set the heater at 120 or less
you are not going to have much more than pi//water
most of the time....especially in the winter


the heater takes off with a decent temp but as cold water
comes into the unit if is not hot enough the temp will
crash its called stratification...

I usualllly set the heater at 130 and let the customer
decide if it is hot enough for them or not....

if turning up your heater a tad bit does not
solve your problem, then its probably a broken off diptube...


anyway turn it up a litttle bit first....


here is a gas temp guide from my site

http://www.weilhammerplumbing.com/galleryiii/

I always set them at 120 degrees and not one degree hotter. The difference in burn time between 120 and 130 is scary.

The plumbing inspectors tells us not to even touch the thermostats....wtf?


All gas water heaters usually have a arrow to match to the dial indicator....that's what I set them to and the customer is free to turn them up after I leave. It's mentioned as a disclosure any time one is messed with.

My city requires a tempering valve on all new WH installations. Seems a little funky, since they're adjustable, too, but hey, you do what you have to. They come from the factory adjusted to 119-degrees.

None of this necessarily answers your question about how low the water will get before the WH thermostat turns on. I've never checked the spec sheets, I'm not sure it says.

range

Gas thermostats normally have about a 20 degree differential. As far as not touching the thermostats, every gas or electric heater I have installed in recent years comes from the factory set to its lowest point. If it is not adjusted the customer doesn't get any hot water.

will install a tempering valve

seems like the right thing to do.

My local supplier sold me a Caleffi 3/4" valve that looks cool, will pipe that in soon. I intend to set it at 120 and the tank at about 140, so in theory my hot water output should be more consistent

Hotter water = more stored energy. Tempering valve = safer since you should never see that high temperature. You'll get a longer run at a constant temperature with the tempering valve and hotter water. The best way to even it out is with a temperature controlled shower valve in addition to the tempering valve, though. This acts sort of like an additional tempering valve, but since the setting is lower, typically in the 102-105 degree range, you'll get even longer shower(s) without having to adjust the valve.