Pentari ETI 400 Heater has HLS code

[TPREY97]

Moved from here.
I have a pentair ETI 400 pool/spa heater. I've replaced the flue stack sensor, thermal sensor and the HLS still won't fire up and heat the water. I've been told there wasn't enough water pressure but after increasing the water flow. The heat still won't fire. And shows the HLS fault code. Has anyone ran into this problem?

 

[ajw22]

Welcome to TFP.

What pump do you have?

Is the pump and heater conto automation?

Please create your signature with details of your pool and equipment.

Post pics of your equipment pad.

 

[Mackboron]

Moved from here.
I have a pentair ETI 400 pool/spa heater. I've replaced the flue stack sensor, thermal sensor and the HLS still won't fire up and heat the water. I've been told there wasn't enough water pressure but after increasing the water flow. The heat still won't fire. And shows the HLS fault code. Has anyone ran into this problem?

Did you figure this out?

 

[Mastalx]

Curious as well to know if you figured this out. By the way, how do you increase water pressure?