Banging noise from heater (on) but….

[amati5]

It happened only when I diverted the return to the spa jets. I realized the 3 possibilities are the low gas pressure, bad pressure switch and low water flow. But since it only happened when I diverted the return flow to the spa jets I think it must be something wrong with the water flow. It made no difference if water pulled from pool or spa. Is it because it’s too restricted due to the jets? It worked before with older 2-speed pump (at full speed) and this is the first time with variable speed pump. The speed was set at 2500 rpm and I could see strong return jets in the spa.

the heater is Hayward H400 series.

thx

 

[ajw22]

What model VS pump are we discussing?

The banging is water boiling in the heater due to low water flow.

Check that no Water is bypassing the heater through any bypass valves.

Increase the RPM on your VS pump.

Post pics of your equipment pad.

 

[amati5]

There is no heater bypass valve. The pump is EC-011028. The noise and the shake is from the intake pipe of the heater (red arrow). If I increase the rpm but the spa jets still restrict the flow will it make a difference? I will certainly try. Oh, forgot to mention I cleaned the filter too hoping to improve the flow..

thx

 

[ajw22]

No filter model is listed in your signature. Please add it.

When does the banging happen?

As soon as the heater lights?

After the water reaches a certain temperature?

 

[amati5]

just tested With 3000rpm and it works fine. Thx for the suggestion. I didnt know it takes that much flow for the heater to work properly. I thought Á long as the ”normal” light is on, it’s good to go.

my filter is Pentair Clean and Clear+ 420. Will add to my signature. Thx

 

[ajw22]

What heater model do you have? That is not in your signature either.

Is your waterfall on when you run the heater and have the problem?

 

[amati5]

The waterfall was on and off, made no difference. It’s completely independent, running from another pump.
The heater is Hayward H400 series.

 

[1poolman1]

It happened only when I diverted the return to the spa jets. I realized the 3 possibilities are the low gas pressure, bad pressure switch and low water flow. But since it only happened when I diverted the return flow to the spa jets I think it must be something wrong with the water flow. It made no difference if water pulled from pool or spa. Is it because it’s too restricted due to the jets? It worked before with older 2-speed pump (at full speed) and this is the first time with variable speed pump. The speed was set at 2500 rpm and I could see strong return jets in the spa.

the heater is Hayward H400 series.

thx

Not unusual if the heater is running and you interrupt the water flow by changing a valve position. That RPM may not be enough going through the jets to keep the heater going.

 

[amati5]

Yes, at 3000rpm I saw a lot more water came out and that was when it stopped making noise.

thx

 

[1poolman1]

Yes, at 3000rpm I saw a lot more water came out and that was when it stopped making noise.

thx

As every pool is different, you've found what your system takes to work properly.