I just replaced the heater (coil and housing) unit and pressure switch on a Proshield module. When powering up and resetting the thermostat, the heater "indication" light does not come on. There has been no improvement in the units heating capability. What am I missing?

I assume you're talking about the topside control "Heat" indicator. All that means is that the thermostat up top is telling the controller to heat the water.

What you're missing is that the relay circuitry that sends power to the heater element obviously isn't sending it. There should be a contactor (large relay) that is connected directly to the heater element. If that contactor does not click (or thunk or clack) when you turn the thermostat up, then the element is not going to get power to it.

The thermostat basically will send power THRU the pressure switch (and possibly the high limit switch) before it gets to the contactor (coil) that sends power to the heater element.

Upload a picture of the guts of this thing and I'll give you some info on what to do if you can't figure it out.

Thanks for the quick response. When I plug the unit in I get that Thunk and clack noise referenced in you reply. I will get a picture of the box sent in ASAP. Is the relay physically a part of the High Pressure Switch or is it located separate from that component?

Since you were referring to a Proshield version... here's one of the very early models.. But if you're only getting the noise on power up, and not when you vary the topside thermostat, then I would immediately suspect the topside controller/thermostat sensor etc up there.

Hmm. Re-reading your original post I can't believe I missed this. So, on the Topside control (at the spa as you're sitting in it), you get no light indication for "HEAT" when you turn up the thermostat.....

Do you get a 'Jets' indicator light, or a 'Blower' or ? Other indicators as you activate them? If you do, then the topside panel has neutral and power from the sources to activate the indicators, but the thermostat (INSIDE THE TOPSIDE control panel) is not operating correctly, or the main power line (black one on the 5 or 6 pin connector to it) doesn't have any power going to it like it should 24/7.

That's my best guess on this right now.

The indicator lights for the water and air pumps work when activated. I ordered the 20a type "G" fuse for the jets and replaced the blown fuses both 10a and 20a. When powering up I get the clacking noise and now the indicator light for the heater (on the control) box will iluminate briefly when turning off the jets.

I read in another posting about possible issues with air in the line causing a false pressure reading and stopping the heater function. There is a bubble in a tube that rises up towards the top side dial. Can this be a cause of the problems and where is the bleeder valve to cyphon out the air?

Some of the tubes are fouled by bacterial growth due to long down time (couldn't find the fuses in stores to save my life). I probably need to bleed out some air in the lines to allow proper flow and chemicals to clean out fungal growths as well.

The JPG is helpful. I will point out that our model is a little newer and has the coil unit inside the box with the pressure sensor directly mounted. The coil housing sticks out of the side where the hoses lead to the water pump. My JPG will be coming soon. Thanks again for your responses. This is good stuff!!!

I would like to take a shot at this, if I may. Have you tried to jump out the pressure switch? I would take the two wires off the pressure switch, and short them together, but ONLY AS A TEST... MAKE SURE YOU DON'T LEAVE IT LIKE THIS. If the heater stays on when you do this, then you very likely have a bad pressure switch. You can adjust the switch by turning the knurled black knob (may have a drop of silicone on it to keep it from turning, which you would have to remove first) counter clockwise. The switch may have become weak or is ineffective all together. If you have a tube going to the switch, and if there is air in that tube, it won't make a difference. When pressurized water enters the tube, it also pressurizes the air to the same PSI and the switch will still function normally.

Thanks again for the reply. I tried adjusting the wheel on the pressure switch and everything is working now. What I eould like to ask is how can I adjust this wheel so I have the correct setting for factory specs.

An additional porblem came up when the jets were fired after an extended idle period. Some of the spinner nozzles blew out of their housings sending the ball bearings into the tub. I've collected all the parts and need to re-assemble.

Any Hints? Your help has been greatly appreciated. Thanks for being there. I'll mention your company to my clients (new home buyers) in Atlanta. I work for a nationally known bank doing mortgages for people who buy from builders.

As far as I know, there isn't a "factory spec" on the pressure switches. Basically they are only there to ensure you have waterflow so your heating element doesn't burn out. As long as you have adequate flow, just adjust your pressure switch so it just turns on, then another 1/2 turn counter clockwise. That will set your switch to what it right for your applicaton.

Regarding your jet inserts blowing out and the bearings comming loose, throw them away and replace the whole insert. The only way that can happen is if the inserts are worn out. I've had those types of jets before and I spent several hours trying to get them back together. I had no luck. I just replaced them. They weren't all that expensive and it saved a lot of headaches.