u/Infamous-Package9436

WTF am I doing.

I'm building a custom shower pan and the more videos I watch the more confused I get.

I've seen like 4 different methods and now my brain is soup.

Do I:

- Put the mud bed down FIRST and make the slope

- Then PVC liner

- Then tile stuff

OR is it:

- Concrete floor

- PVC liner

- THEN the mud bed mix

- Then tile

I swear every YouTube video contradicts the last one.

I'm trying to do this correctly and not create a moldy leaking disaster hidden under tile 6 months from now.

Help me out before I waterproof myself into a corner.

I’ve been troubleshooting an older hot tub that would maintain temp but never actually get hot. Wanted to share what I found and get a sanity check before I finish the repair.

System:

Gecko control board: Gecko 9911-500102 Rev E

240V setup

1 main pump (Aqua-Flo XP2), 1 circ pump (Laing E5), blower

Standard stainless heater tube

Symptoms:

Tub stays warm but won’t reach setpoint

No error codes

Flow is good (circ pump running steady, filter clean)

Electrical measurements:

Input (L1–L2): ~245V ✔

Heater output (L1–L2): ~107V ❌

L2 to ground: ~121V ✔

L1 to ground: ~12V ❌

So effectively the heater is only getting one leg of power.

Diagnosis:This doesn’t behave like a flow switch or sensor issue because the system is clearly trying to heat. It also doesn’t match a blown fuse (not open circuit).

It points to one leg of the heater not being switched through the board.

On the control board, heater power is switched by two relays:

Zettler AZ2150-1A-24DEF (x2)

Based on tracing the board:

One relay feeds L1

One relay feeds L2

Given the voltage readings, the L1 relay is likely not closing or has high-resistance contacts (burned/pitted).

Proposed fix:

Pull board

Replace both Zettler relays (same age, same load cycles)

Clean and re-seat heater terminals

Re-test voltage at heater output

Replacement relay I’m using:

AZ2150-1A-24DEF (24V coil, SPST-NO, ≥30A @ 240VAC)

Why not replace the board?

This is an older Gecko system and full replacement kits are getting expensive relative to the tub value. Relay swap is a low-cost attempt (~$10–15) and the board shows no obvious trace damage.

Question for the group:

Anyone seen these AZ2150 relays fail this way (partial voltage / high resistance)?

Anything else I should inspect before reinstalling?

Appreciate any feedback. I’ll update with results after the swap.