Hello,
I have a Emerald Spa Model 995 DS3/4 and recently encountered an issue with my spa in that the low speed pump will not turn on. I see the indication on the control panel indicate it is on and when the control panel light comes on I do hear a click from the circuit board box, but no pump action. High speed pump comes on without a problem. Have tried all the usual troubleshooting, plus some:
1. removed filters and see if low pump comes on, no luck (though I actually just completed draining, cleaning and refilling the spa, which included filter cleaning/replacement so I know it isn't a dirty filter)
2. re-primed the pump (since recently did drain, clean, refill, ensured no airlock in pump; but if high speed running with excellent flow from jets, then would expect no airlock present as well)
3. checked/bypassed pressure switch (with pump on high speed, I do get continuity from pressure switch; have no continuity from pressure switch on low speed, probably because pump doesn't turn on at all, so no flow to see it have continuity; "jumping" the pressure switch cables to circuit board box didn't make it work either)
4. Swapped the black and red cables to pump, to ensure pump low speed actually works (so when I turned on high speed from control panel, the low speed did work; in addition, just replaced this pump about 2 years ago, so wouldn't expect for it to have gone bad already).

I believe I've come down to it now possibly being a circuit board problem (Balboa Instruments 650X Series, PN-25500, chip DS34R1B)? Or is there something else I should be checking?

Just checked voltage from the circuit board to the pump... when low speed on, red-black, red-white and black-white all measure 0.18VAC. High speed on I get Red-Black 240VAC, Red-White 240VAC, Black-White 9VAC. Does this confirm I have a circuit board problem?

If is circuit board problem, I've seen some websites that can repair circuit boards, some selling new circuit board and others saying should just buy an entirely new spa pack. Would like your opinion on which method is best?

Thanks in advance for your time,
Kevin

It certainly sounds to be a circuit board problem, but look closesly for damaged wire somewhere too.
Try cleaning the low speed relay on the board? A piece of notebook paper slid between the points on the contactor might remove some small carbon deposits, if that's the issue.

Good luck!

Thanks for the quick response... did check all wires and see no sign of damage. I tried cleaning off the low speed relay... but it didn't seem that dirty. However, I was able to get the low speed pump to turn on, when I pushed the bottom of the relay up to make contact with the coil?... But won't stay engaged, so I would guess the relay has gone bad as it doesn't look like it moves to engage properly?

Would you recommend replacing the entire board, sending the board out to get the relay replaced, or buying an new spa pack?

I certainly don't think I need an new spa pack. So I guess I'll probably pursue replacing the entire board (as recommended by the Emeral Spa tech support, cost about $450) and/or sending the existing board out for repair (seems like many sites on web max charge is $175). If I do both, at least I'll have a spare board in case the new one ends up going out prematurely