Why might it take *LONGER* for hot water to get hot after water heater install...

[Tripp Knightly]

I just got a new water heater, replaced due to age (15 years) and chronic sediment / rust. Both new and old were 40 gal (gas) and thermostats were set to recommended temp setting. The only the other thing that is different is a change to configuration of hot water output pipes. And maybe this is the real cause... bear w/ me on some other info.

Originally hot water was delivered from 2 places on the tank. 1 from the top, the usual place. Also, oddly, from a pipe coming off the

*bottom* of the heater before the drain spigot. My guess is previous owner thought it would be easier to add new service to this location rather than trying to splice into the existing service to the tank. I had my plumber just go ahead and cut/splice this service pipe to a T junction at the top of the tank with the other service coming off the top. In effect this shortened the service originally coming off the bottom by ~ 5 feet max.

My house doesn't have a ready-hot water circulation system / pump (which I understand involves this kind of second connection to the heater bottom).

So, I'm at a loss as to why it should take longer for water to get hot @ shower. It is getting colder outside, but I live in San Francisco, so the temperature really hasn't changed *that* much to make me think it's the weather.

I suppose 1 explanation is thermostat on old was unreliable, heating hotter than that prescribed by recommended setting on dial. Any other ideas? The pipe splicing thing seems interesting too, though how that'd cause it is beside me.

[Joseph Meehan]

I would guess the old system used thermo siphoning to circulate the water in the pipes using the fact that warm water is lighter than cold giving you much the same results as using a pump.

You should save a little on energy cost, but as you have noticed it will take longer for hot water.

[HA HA Budys Here]

-Hot water is never tapped from the bottom of the tank.

-99% chance this T connection to the bottom drain was the return leg of a "thermosiphon" hot water circulation system which worked well w/o a pump.

[Kevin Ricks]

I recently installed a new water heater in my house. I installed the dielectric unions with the internal check valves. They contain ball bearings of some sort which is supposed to keep hot water from migrating out of the tank both at the cold inlet and hot outlet when not in use. With these installed, it now takes noticeably longer for hot water to get to the destinations. These do produce a kind of an annoying ratcheting noise at the water heater when water is flowing. Maybe your plumber installed something like these?

Kevin

[Michael Baugh]

With the newer lo-flow fixtures, I'm a believer in reducing the size of the supply lines from the water heater. Makes the water in the line clear quicker, with faster delivery of hot water, less wasted water.

[Tripp Knightly]

Thanks. Well, that's got to explain it. What a cool trick (no pun intended). My plumber spent time looking for a non-existent electric circ pump, but didn't offer thermosiphon explanation. I have a finished basement, so it's not possible to see all the pipes and I incorrectly concluded, based on pipes going in different directions, that they were serving different groups of destinations.

Doh!!

I suppose reconnecting to original spec incl flapper valve would be as good as any for a first-time DIY plumbing repair if I decide I want faster hot. I probably will - it worked pretty well!

I assume that if I have some sinks at basement level (ie, same level as heater), they just won't get the fast hot from the thermosiphoning loop.