When the water pressure drops enough for the switch to start the well pump, we get a short blast of hot followed by a short blast of cold water (maybe 1 second each) with a slight hesitation in between them (i.e. drop in pressure). This started roughly 6 months ago and got continually worse until it the pump was cycling about every 10 seconds.
The research I did indicated a waterlogged pressure tank, so I replaced it, assuming a new tank would solve the problem. The new tank reduced the cycle time back to normal (maybe every couple of minutes when showering), but did not eliminate the hot/cold blasts. I tried adding several pounds of air to the tank and I tried removing several pounds of air from the tank and neither seemed to make any difference. Anyone have any ideas?
I did not shut off the pump and open the lines when I changed the tank pressure, so I don’t have an accurate precharge psi.
Thanks for any help.
Shane
Replies
The only thing I can figure out here is that somehow the hot line is back feeding the pump. This should not happen as it indicates that the hot water system is somehow pressurized. You should not have needed to replace your pressure tank, just recharge the air.
You really need to depressurize your system and properly pre-charge the tank. The pressure in the tank needs to be set a few pounds under the cut in pressure on the pump.
Erich
Could be a leak between the tank and pump...pitless adapter or O ring? Pop the cap off the well head and listen for water draining when the pump is off, or activate the pump and listen for pressurized water. Been there before...
If that is the cause, then a vacuum is being created by the leak down and drawing the domestic HW back into the cold feed. A check valve at the cold feed to the HW heater would prevent the short blast of hot water.
What is the capacity of the new storage tank? With only a shower running, the pump shouldn't have to cycle so often...>>The new tank reduced the cycle time back to normal (maybe every couple of minutes when showering),<<
The symptoms you give sure sound like a leak is the cause...might even be the footvalve on then pump.
The tank is a small one - maybe 30 gallon? I would have gotten a bigger one when I replaced it, but it was covered under warranty and I couldn't upgrade. And I know there is a leak out of a yard hydrant - we just hooked a soaker hose to it to water the garden all summer. I've got the parts to fix it before winter - its not a very big leak though and I doubt it would cause the tank to over-cycle much.
Thanks for the advice - it sounds like I need to check for another leak at the well or pump, and possibly recharge the p tank.
If you do recharge the tank, drain the tank completely...water and air... and then recharge the press to 2psi less than what the pump cut in press is set to.
30 gallons is plenty...find the leak. The soaker hose wouldn't cause your problem unless your running the well dry and sucking air. It could cause the repeated pump cycles, but not the short spurts of hot water.