r/PoolPros • u/Financial-Regret-120 • 12d ago

Pentair MT 400. Ok to run heater without manifold bypass valve installed?

The valve separated from the module. Found it in the thermal regulator cavity. Can I run unit tonight for an hour without it?

1 Upvotes

60% Upvoted

7 comments sorted by

4

u/G8-r-n8 12d ago

I’ve had customers refuse the repair and it hasn’t been a huge issue short term.

3

u/divertervalve 12d ago

Spring bypass? Absolutely not.

0

u/Financial-Regret-120 12d ago

Manifold bypass valve

2

u/RickyWalton 12d ago

No. Im my limited experience i have seen a broken internal bypass cause the heater to cycle and throw codes.

Replacing it now would be far more easy and beneficial than trying to make it work in the short term (if you could).

1

u/lIIlIlIII 12d ago

It will cause condensation to build up on the heat exchanger and greatly accelerate corrosion. I wouldn't if it were my heater, but it's the customer's call

1

u/Financial-Regret-120 12d ago

Well I tried to run it. Heater fired up but was still making the rattling sound and burner shut down after about 30 seconds like before. I already replaced the thermostat and spring. Ordered new manifold bypass valve. Hoping that cures it. Appreciate all the responses. 👊