RobFire Posted June 30, 2010 Report Share Posted June 30, 2010 My below ground pool heater is making strange noises this year. When heating it moans, I can change the pitch by adjusting the throttling valves in/out of the heat exchanger. When set point temperature is reached I have also noticed that when the heater turns on, the heater will start to vibrate and shake for 5 seconds, then continues to moan. If the heater is not on and water is just passing thru the heat exchanger -- no noise. Quote Link to comment Share on other sites More sharing options...
Pool Clown Posted June 30, 2010 Report Share Posted June 30, 2010 Sounds like the thermostatic by-pass. what kind of heater is this? Did you by chance change the pump this past year? Quote Link to comment Share on other sites More sharing options...
RobFire Posted June 30, 2010 Author Report Share Posted June 30, 2010 The pump was changed a couple of years ago. However, at end of last year season, the heater was no longer turning on and pool temperature dropped. This year I found and replaced a faulty pressure sensor, replaced the thermocouple\pilot assembly as well. Heater works fine now except for the moaning and groaning. While working on the heater, I was draining the lines by removing a spring loaded device bolted on to the side of the heat exchanger (probably the thermostat device??). Does the device have a preferred orientation, could be mounted either way? The heater is a MIN/MAX unit. How do you determine if that is faulty? Quote Link to comment Share on other sites More sharing options...
Dr. Spa Posted June 30, 2010 Report Share Posted June 30, 2010 The spring loaded devise is the bypass valve. It controls the actual amount of water that goes through the heat exchanger. It sounds like there's a problem with the bypass valve, and it's not diverting enough water through the exchanger, and the water in the exchanger is approaching the boiling point, which it what's causing the noise....or the exchanger is clogging up Quote Link to comment Share on other sites More sharing options...
Pool Clown Posted July 1, 2010 Report Share Posted July 1, 2010 Yep, the bypass is opening enough where it will make noise (a groan) kinda like when you whistle, you have to have your lips open just right to make sound, only in the case of your heater, it's a vibration. Could be something as simple as a different flow rate (new pump), or the thermostat-bypass has begun to fail, and therefore is not opening the same amount as it used to, and subsequently is causing the heater to begin to vibrate, or shake as the water begins to boil (washing machine syndrome). Quote Link to comment Share on other sites More sharing options...
RobFire Posted July 1, 2010 Author Report Share Posted July 1, 2010 Thanks for your help, I will get a replacement bypass valve. FYI - I also did install a new salt generator and there were some changes (tromboned) in the piping on the discharge side involved that might go to the flow rate changes? Quote Link to comment Share on other sites More sharing options...
Pool Clown Posted July 1, 2010 Report Share Posted July 1, 2010 Yes, that would make a difference. The extra piping means the water has to travel farther which would equate to lower flow. Would this be enough to cause your problem? Perhaps, all systems are different with this respect. If it ran noiseless before the unit was installed then now it makes noise? I would at least take the by-pass out and inspect it. Be careful when ordering. Some heaters have a mechanical (flow) by-pass and another one for temperature. Some are combined. Quote Link to comment Share on other sites More sharing options...
Arner Pool Service Posted July 2, 2010 Report Share Posted July 2, 2010 My below ground pool heater is making strange noises this year. When heating it moans, I can change the pitch by adjusting the throttling valves in/out of the heat exchanger. When set point temperature is reached I have also noticed that when the heater turns on, the heater will start to vibrate and shake for 5 seconds, then continues to moan. If the heater is not on and water is just passing thru the heat exchanger -- no noise. You are not getting enough water flow thru heater, trying backwashing filter or clean cartridge. May also be a bad heater by-pass. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.