HVAC technicians... Water

[johnt2_2002]

Scenario

Basement flooded including all components in the blower compartment..


I've taken the appropriate steps I think, but what would you guys do in this scenario...

For code reference in Ontario--I've used 4.5.5

[TKG26]

I am good with that one. Pretty much the only acceptable reactivation would be replacement of any wet electrical components. Motor, Circuit board and capacitor. Wiring harness as well possibly.

[johnt2_2002]

Yeah, I've issued an atag as well. Circuit board, transformer, run capacitor, blower motor, and, on this Goodman unit, Aux. limit switch were quoted for replacement. I did not attempt to turn it on for safety reasons...

Goodman's warranty was voided on the unit as well....

I thought about the wiring harness but couldn't see why it would neccessary, what's your reasoning?

[wgauci]

I'm a commercial guy and I haven't touched a residential furnace in years, but from my point of view, if the electrical parts are dried out and the circuits are tested and found to be electrically sound, why change them? This winter alone, I have had several rooftop 600v units that had blown snow and water blown into the electrical sections during storms. Carriers are particularly susceptible to this. Anyhow, this usually results in the top of one of the contactors shorting out across the line side. Once the shorted part is replaced and the rest of the parts are dried out, I don't have any other issues with the units. This includes the ignition boards and main control boards. Even motors, I routinely find motors immersed in water doing a lot of refrigeration service and drying them out is all it takes usually.

Also, I used to work for a company that had a contract with an insurance company and I came across flooded furnaces every week and more often than not, drying out the furnace was all it took to get them up and running.

[TKG26]

john only the wiring harnesses that have molex connectors like a 9pin.. if dry re-use them, but i have seen some get rusty from damp basements. and cause issues

wgauci its a judgment call for sure, but by code a flooded appliance can warrant replacing water damaged parts.. i dont have the code or wording in front of me.

[ScaryBob]

Water would be especially bad for relay contacts, due to corrosion or residual dirt and salts. What will happen in a month when use plus dirt or salts cause the contact deterioration? In the trade, we didn't let motors get wet or damp because they could catch fire or explode instead of start when power was applied. Water and windings do not mix well. Never mind what might happen to gas valves. Do you really want to take the chance that a water damaged gas valve sticks open? I wouldn't trust a furnace, especially a high efficiency furnace, that had been immersed in water. It might start now but what about 3, 6 or 12 months from now? How do you test that all the safety circuits are working properly? I would be very upset if I got stuck with a series of repair bills because water parts started failing after the fact.

[wgauci]

Didn't want to give the wrong impression Scary, I am well aware of what water can do to motors and anything else. I've done nothing but HVACR service for over 25 years and there's not much I haven't come across. I really was just giving examples of what I have experienced. My point being that just because a wiring harness, motor or a limit switch gets wet, it doesn't stop it from functioning after it's been properly dried. A lot of the newer printed circuit boards now also have a thin silicon coating applied to prevent water damage.

As for safety circuits, after any potential damage or major service for that matter, all safety circuits must be tested. Firing the burners and disabling the blower to ensure the high limits are working, also blocking the vents and ensuring all pressure switches function is required. Anything less and you're the one sitting in court answering for your actions.

For the record though, I do routinely see motors immersed in water and operating. The water does more damage to the bearing and rotor than it does to the windings.

[ScaryBob]

The point I am trying to make is that damage may not be evident at first. I don't trust wiring harnesses at the best of times. Moisture sets up electrolytic action or can create thin oxide layers that cause intermittent contact. A small piece of corrosion or dirt, in a motor bearing for example, may not prevent operation now but can easily lead to a failed part in a few weeks or months. Motor windings can develop shorts that may not show up right away but cause overheating and failure down the road. The specs for standard electronics and electrical parts almost always specify no exposure to condensing moisture. Immersion in water, especially flood water is way out of spec.

[txv]

Circuit boards, safeties, gas valves, metal spade connectors, and motors should be replaced for sure.

[johnt2_2002]

Thanks everyone for the replies.

I've quoted only the parts that were under water to be replaced.
I'm concerned now about the gas valve. It was not under water so I didn't think it would be a problem..

Well if we get the repair job... I'll be sure to double check the gas valve as well as all other safeties on the unit.....

[txv]

If the gas valve stayed dry it might be okay. (I assumed that it did)

[johnt2_2002]

Yeah the gas valve stayed dry. Just the parts I mentioned were under water......

[38racing]

Originally Posted by johnt2_2002

Thanks everyone for the replies.

I've quoted only the parts that were under water to be replaced.
I'm concerned now about the gas valve. It was not under water so I didn't think it would be a problem..

Well if we get the repair job... I'll be sure to double check the gas valve as well as all other safeties on the unit.....

i suspect it adds up to more than the price of a new installed furnace.

[johnt2_2002]

The repair is about 1/4 the price of a newly installed furnace. Our company pricing is higher than most of the other companies out there. But, as the saying goes, you get what you pay for.