Hot water issue

Hi everyone,

There has been an annoying plumbing issue develop recently - no hot water! However, as far as I can tell it's not necessarily a hot water heater issue. I thought it was at first, but I've come to realize that I can get the hot water going again if I turn on the shower and set the water temperature to output hot water. So a typical day would go like this:

- wake up, take shower. I always have hot water in the shower.
- go about my day. Use other faucets (kitchen, bathroom, laundry room). 80% of the time I won't be able to get hot water.
- if I need hot water, I can turn on the shower and run it until the water gets hot (10 seconds or so), then I can get hot water elsewhere.
- if I don't need hot water, I just ignore it and get it going again when I take a shower the next morning.

Hopefully this description of the issue makes the problem relatively easy to diagnose. By the way, the home and hot water heater are both four years old.

Thanks!

Do you have a Mixet brand shower valve?

It's a Moen. It looks like this: http://www.moen.com/adler/chrome-posi-temp-r-tub-shower/_/R-CONSUMER%3AL82694

There are several POSSIBLE causes, but someone would have to be at the house to sort them out to see which problem you are actually having. A 4 year old house would NOT have a Mixet valve.

Are you saying that if you set a faucet to hot only it never gets hot? Or are you saying that you aren't willing to wait that long? Is this a standard tank/storage type water heater?

I've got temp sensitive valves on my shower, so I can turn it on, walk away, it reaches temp, then it shuts to a trickle until I get in and pull the release which starts full flow again.

Distance from the water heater is important when considering how long it takes for water to reach temp. My kitchen is the longest run and it takes about 45 secs. to reach temp. If I want a quick hot water draw there I'm SOL. Insulating the piping will help a little, moreso on subsequent draws with short times in between. The effect of insulation is quite noticeable as I can feel the difference in bands of pipe leading to the kitchen that are hidden (uninsulated) vs. both ends that are insulated--as in feeling warm, cold, then warm, and then hot again.

Yes, if set to hot the water never gets hot. It gets warm, but barely. And it feels like the longer I let it go, the colder it gets. It doesn't get cold, but colder than when I start running it.

Now the longest I've continued running the water is maybe 1 or 2 minutes. I could let it go for longer if you guys think that might tell us something, but getting hot water has until recently never been a concern. I'd say it usually takes 20 seconds tops no matter from which faucet I use, so going one full minute without hot water is what I'd consider abnormal.

Finally, yes, it's a standard tank water heater, using natural gas.