cold water from hot water tank

[MasterPlumbersKeymaster]

I purchased a Ruud pacemaker water heater about six months ago and it also was installed with a small reserve tank. I am having a problem that I am not sure is related to the type of water heater, the reserve or is to be expected. If we have not used hot water for a period of time, say overnight, the water is cold. In order to get hot water, we need to run the hot water for several minutes. We then hear the heater turn on and in a few minutes, we have hot water. It will then remain hot for most of the day. What do you think?
Thanks for your help!
Rwelch

[DUNBARParticipant]

Sounds like the thermostat is malfunctioning on this heater.

Be more descriptive on whether it is electric or gas ……how many gallons and purpose for reserve tank.

[nicktheplumberParticipant]

I would think that you have a long run of hot water pipe, and that the standing water in this pipe run is just cooling off…so you have to clear the cool water before you get a good hot water flow. If that is the case, you could consider installing a hot water recirculation pump in the line and/or insulating your hot water pipes. However, you also implay that this was not a problem before your new Ruud water heater was installed. So maybe you need to adjust your Ruud thermostat up a couple of notches and/or insulate the tank.

NtP

[SelgasParticipant]

Your problem is with the thermostat – to be absolutely accurate the differential bewteen the cut in and cut out settings are way too great.
If it is a gas water heater then the whole gas valve control has to be replaced with one that has less than a 12 degrees differential built in.
If it is an electric one then some of them can be adjusted but most cases a new thermostat usually fixes the problem.

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Selgas Services Ltd
Craftsman Gasfitters, Plumbers, Electrical Service Technicians

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