Why would a water heater make a whistling noise?

Answer by  hoffmanfam (51)

Could be because the water is too hot and is building up pressure like a tea kettle does and the steam is just trying to escape. It could also be clogged in an escape valve.

Answer by  whutt316 (68)

It may be pressure being relieved from the relief valve. It could also be trapped air in your water lines. If it continues have a professional look at it. It really sounds like its the pressure relief valve to me though.

Answer by  debiup (25)

When the heater starts whistling it usually means there is sediment in the bottom and it's restricting the proper flow. It is probably time for a new heater.

Answer by  elden (116)

The first thing I would check would be the vent. If you hear the noise just after you use some water, then the vent could be partially blocked and it would whistle when the tank is filling. A lot of things could be blocking (bug,dirt,lint,cobweb). If you hear it all the time then it's something electrical.

Answer by  hurricore (66)

Sound like steam to me. it can also be the exhaust vent being obstructed or the pressure relief valve. You may have noticed an increase in your energy bill?

Answer by  Keith054 (16)

One reason could be that there is a pop off valve on all hot water heaters, the popoff on yours could be getting bad and need to be replaced.

Answer by  mastergas (0)

Its called thermal expansion! u need a expansion tank on ur w/h. a one gallon tank will handle up to a 50 gallon gas/electric water heater. have a certified plumber to install. also ck ur water regulator & relief valve!