Water heater cycles cold to hot

[Green-chili-stu]

My 2 year old Fleetwood E2 has started cycling its hot water delivery at the sink faucet (haven't checked the showers). The hot to cold cycling seems to coincide with the water pump cycling on and off. When I first noticed this over our last weekend outing, I thought it was related to the water heater flame/pilot continuing to "blow out". I think I fixed that problem though by turning up the pilot light setting.

Came home, set up for some testing, got the water heater going, and then noticed the above described temperature cycling of the water at the sink faucet in harmony with the pump on/off cycle.

Any Clues?

Thanks ahead of time.

GC Stu

[AustinBoston]

Hmm.  Does your E2 have a pressure tank?  I know when my water pump is on, it's on until the water is turned off, then comes on as soon as the water is turned back on.

[speculation mode]
In any case, I would susupect a partial blockage of the hot water lines, so that you are getting more water through the cold side when the pump is on.
[/speculation mode]

Try setting the WH to it's lowest setting (so you don't get burned), then repeating the test with only the hot water faucet on.

Austin

[wavery]

It takes awhile for the hot water to get to the faucet. If the faucet is off for  15 minutes, the water in the line will cool. The next time that you turn the hot water on, you will need to wait for the cooled water to exit the hoses until you again get hot water.

I'm not sure if that is what you are referring to but if it is, you may want to consider insulating your hot water hose all the way from the h/w tank to the faucet. That will increase the amount of time that it takes the water to cool in the line. You can buy that insulation in 8' lengths at any home improvement store. I would recommend the type that is made for AC pipes. It comes in smaller diameters and is far more efficient. However, it is a Little more expensive.

[JimQPublic]

Water heater bypass valve not fully open (or is it closed?) Or if the bypass uses a check valve it may have failed.

[Green-chili-stu]

Well, looks like JimQPublic got it closer than anyone else. I opened and closed the heater by-pass valve several times, and low and behold - got a steady hot water output again.

Thanks for the help,
GC Stu

PS - Just joined the forum, and I've really enjoyed looking through the Q&A in the Mr. Fix-It category, as well as the others. I'll check back often.

[AustinBoston]

PS - Just joined the forum, and I've really enjoyed looking through the Q&A in the Mr. Fix-It category, as well as the others. I'll check back often.

Be careful, it can be addictive.

Austin