Lukewarm water from water heater

[Pattycake]

I have a 4 year old natural gas 30 gallon Rheem water heater. Since last week, we have had 90-110 degree water at night (which is really the only time we use it). The tap water is coming in at 45 degrees. I live in a hard water area.

I live in the mountains and I am wondering since it has warmed up here that maybe our water supply is coming from some snow runoff and that could be the culprit?

I have maxed out the thermostat. Time for a new water heater? What do I need to check before I go spend $600+ for a new water heater installation?

[Speedy Jim]

Incoming water shouldn't affect the temp setting.

Right after the unit finishes firing, run a Hot tap at just a trickle. Feel the Hot pipe leaving the heater. Is it much hotter than 90-110 deg ?

Let the water run a while. Does the exit pipe grow significanly cooler?

Those tests can help rule in/out a bad dip tube.

If the water leaving is not real hot under any conditions above, it may be the control which has simply "snapped". They are not cheap to replace, but on a 4 year old heater it could be worth the expense.

Jim

[trader4]

Draw enough water to get the WH to fire up. Then shut off the water and wait for the WH burner to go off. If it's then only 90-110 with the WH temp control set way up, then with a 4 yr old unit, I'd say it's most likely the thermostat/valve control assembly is shot. They can be replaced for around $60 or so part cost.

If it reaches full temp, but then goes way down when no water is drawn for a long time, like overnight, that would also indicate a bad thermostat assembly, where there is too big of a delta between on/off.

This also assumes you don't have some strange long hot water pipe run through a cold slab, etc.

[hallerb]

30 gallon tanks are cheap, and even installed shouldnt be 600 bucks.

if the control is bad I would replace the tank and get at least a 40 gallon tank.

have you priced home depot or lowes for tanks?

with real hard water the tank may be filled with sediment, when heating it will make a boiling noise.

I would replace the tank going larger like 50 gallon maximizes the time till it flls with crud again

[Don Young]

Another possibility is a leak in the hot water line somewhere. Check if the heater outlet pipe stays warm for more than about 3 feet from the heater when no hot water is being used.

Don Young

[Sacramento Dave]

A 4 year old water heater should not go bad . It might be just need some new parts. One of mine gave out and it was old I was going to replace it and someone suggested putting a new Thermocouple in it. Less than $10 dollars I was running hot again. This might help a little

Also when I bought this house the owner said the water heater was broken she just had Luke warm water. On moving I had a new water heater, the old tank control was set on Pilot any way took the new one back. Before you ask the owner was operating on Gin fumes

[Deke]

What Dave said.