Hi, last month I just bought a house which came with a hot tub and an older asp 9000 unit. The hot tub was running fine at 104 degrees but adjusting the knob in any direction brought the temperature down to 92-96 degrees and it was difficult finding that “sweet spot” again. Being that it was too cold anyway, I decided to clean it out. I drained it, wiping it down, then refilled it and turned on the heater again but I forgot to open the valve gates again (I closed them to fix a leak). After two days, the hot tub hasn’t heated up one bit. Did I ruin the heater by having it running with the gates closed or does it seem like there was a problem already that could be fixable? I’ve attached a photo of what the heater looks like.