Have you tried cleaning the bottom of the boards? Looks like some flux or small solder particles everywhere.
I see one issue the relay contacts are only rated at 3 amps.

 

I see what looks like a solder blob around D1 on the board with power module removed.

 

Have you tried cleaning the bottom of the boards? Looks like some flux or small solder particles everywhere.
I see one issue the relay contacts are only rated at 3 amps.

You are right, that's why I had to put the red jumper there, little arcing in progress killed that trace.

 

Getting back to the first board with the PS removed does it have the same issue with the solenoid not connected?

 

Yes, that's the one that does it, I even swapped the power supply using the other one, looked way safer to me
The relay 3A rating @120V should be plenty right?

Board 2
cleaned, blob removed, 100nF cap from pin5 to negative added, no change.

 

The relay 3A rating @120V should be plenty right?

No because you say the solenoid valve requires 5.5 amps.
Post a link to the valve.

 

No because you say the solenoid valve requires 5.5 amps.
Post a link to the valve.

Will do, it's rated AC120V/5.5VA on the coil

UPDATED
https://www.aliexpress.com/item/400....order_list.order_list_main.34.2c3d1802BGYMKN

 

This D1 is the one I was speaking of.

 

This D1 is the one I was speaking of.
View attachment 289662

Yes, that's where I sucked away the blob, I can try to replace it, got buch of them.
Also noticed if I leave it on the bench that sometimes it will reset it self without me touching it.
Will swap the diode now.

 

I can't bring up the specs on the 110vac solenoid you posted but 5.5 amps seems like a lot, that's 605 watts where the 12 volt version only uses 6 watts.
Post a photo of the actual valve so I can read the numbers please.

 

I can't bring up the specs on the 110vac solenoid you posted but 5.5 amps seems like a lot, that's 605 watts where the 12 volt version only uses 6 watts.
Post a photo of the actual valve so I can read the numbers please.

Yes, I find the markings strange, I thought 5.5VA was 5 watts so about 50mA @ 120V

Diode replaced, no change
Resistors measured, both good

 

That's correct 5.5VA is around 5 watts or 50ma so the contacts should be fine.
I don't know if you answered the question if board #1 (which is the one with the PS removed and works when holding the wires) works OK if the solenoid and 110vac are not connected.

 

No, didn't even connect the solenoid to that board yet, only listening to the relay and having tester attached to the relay contacts to verify closed/opened.
When connected it will switch on
I can just touch the upper sensor and it will turn off (shouldn't) touching lower does nothing.
If I hold the upper or lower output wire in my finger tips I can control the sensors and it work like it should.

 

How are you actually activating the sensors to test the boards?

 

Just touching the pads with my fingers ( they are in little plastic bags so no contact)

Also measured the sensor output and they still activate correctly just the relay does nothing.
Swapped sensors as well, no difference

 

OK but when first powered up the relay should activate immediately if the sensors are not touched. Is that correct?

 

That's correct

 

OK then touching the LOW sensor should not shut off the relay but touching the HIGH sensor should

 

OK then touching the LOW sensor should not shut off the relay but touching the HIGH sensor should

Yes, you are right!

 

Then the circuit is working correctly.