loud 12vdc water

[sanjaun2]

Hello all, My water system makes horrible chattering sounds when using the 12vdc water. I changed out the pump to a quieter one and installed flex lines on the intake and output lines. It is still horrible. In troubleshooting I found the noise is coming from the tankless water heater. If I close the valve going into the twh 90% of the noise goes away. When I open the the outside door to the heater it is so noisy in there. Probably loud enough to wake neighbor up! I cannot find anything loose anywhere and have run over ten gallons thru it in case there was air trapped in there. any one have any ideas? Thanks.

[Long & Winding road]

OMG. Look up the owners manual for "Girard tankless hot water heater". Someone just posted a link to it the other day. Do you have any Error codes on the temp/ON - Off gauge?

[sanjaun2]

Originally Posted by Long & Winding road

OMG. Look up the owners manual for "Girard tankless hot water heater". Someone just posted a link to it the other day. Do you have any Error codes on the temp/ON - Off gauge?

I have no fault codes. The heater is actually turned off. I was just trying to quiet down the system a semi reasonable level. I'll see if I can find the manual for it but not sure it will help with the hammering noise inside it

[mountainsam]

I would give the manufacturer a call. I am sure they have customer service that can help. Our tankless heater is completely quite.

Does this happen when you are hooked to city water as well as when you use the pump?