Hot Water Heater has a low supply threshold(?)

[tatemfam]

Hey, all! (first time here, so please let me know if this thread belongs elsewhere)

I've scoured the Internet, but I haven't been able to find a solution or even another problem similar to our exact situation.

My wife and I just bought a place. The hot water heater is new and it heats water like a champ. It takes about a full minute to get hot water at the kitchen sink, which is understandable given the distance. However, once hot water comes through, it's REALLY hot. Great!

Now, let's say I turn the hot water off at the sink and wait for 2-3 minutes. When I turn the hot water back on, hot water comes out of the spigot for a split second, then warm water for a few more seconds, then it goes relatively cold and I have to wait another full minute to get fully-heated water again.

The only thing that might be worth noting is that the pipes from the water heater go into the attic (we live in a one-story slab ranch). I haven't checked in the attic to see if the pipes are fully insulated, but even if they aren't insulated, I can't imagine the water in the pipes going from scalding hot to cold in 2-3 minutes.

I can't figure out how or why the water in the hot supply pipe is cooling so quickly, and it's the same for every room in the house. If the wife takes a hot shower, then by the time she dries off and makes it out, I have to wait a full minute for hot water again. Any ideas?

Thanks! )

 

[Terry]

Attics are ventilated, so whatever the temperature is outside, that's how warm or cold your pipes will be. It doesn't take long as you have found.
Insulating the pipes will help. Adding a recirc to the system would cut down on the wait.

 

[Sponsor]

 

[tatemfam]

Thanks for the tip, Terry! I'll have to check for insulation post haste. Glad to know there probably isn't a hot water goblin in the attic.

 

[Phog]

Hey, all! (first time here, so please let me know if this thread belongs elsewhere)

I've scoured the Internet, but I haven't been able to find a solution or even another problem similar to our exact situation.

My wife and I just bought a place. The hot water heater is new and it heats water like a champ. It takes about a full minute to get hot water at the kitchen sink, which is understandable given the distance. However, once hot water comes through, it's REALLY hot. Great!

Now, let's say I turn the hot water off at the sink and wait for 2-3 minutes. When I turn the hot water back on, hot water comes out of the spigot for a split second, then warm water for a few more seconds, then it goes relatively cold and I have to wait another full minute to get fully-heated water again.

The only thing that might be worth noting is that the pipes from the water heater go into the attic (we live in a one-story slab ranch). I haven't checked in the attic to see if the pipes are fully insulated, but even if they aren't insulated, I can't imagine the water in the pipes going from scalding hot to cold in 2-3 minutes.

I can't figure out how or why the water in the hot supply pipe is cooling so quickly, and it's the same for every room in the house. If the wife takes a hot shower, then by the time she dries off and makes it out, I have to wait a full minute for hot water again. Any ideas?

Thanks! )

Hello tatemfam,

I notice you posted this in the "tank" water heater section of these forums (as opposed to the "tankless"). So I must assume you have a traditional tank-type water heater. However, since you didn't explicitly say what you have, I just wanted to mention that IF you have a tankless (on-demand) unit, the behavior you describe is normal & expected. Look up "cold water sandwich" and you'll find numerous explanations of why this occurs. The recirc loop that Terry outlined above still will fix your problem either way. But for a tankless unit, pipe insulation alone won't do much, you'll still get the cold water sandwich due to the nature of how tankless systems operate.

 

[Master Plumber Mark]

If you live in Virginia, I would think your water lines are already insulated if they go through the attic...
rarely do you see water lines up in attics in areas where the winter temps get down to -30 in the winter...

you would be wise to check them out before the next winter is upon us because most Attics are hot in the summer
and BITTER COLD in the winter..... You should not be losing heat being its probably 90 in the attic at this time.... Also condensation will happen on un-insulated pipes and sweating can stain ceilings... you better insulate ALL water lines in
your attic...






......