Noisy Powervent

BoilerBoy

Thanks for any help in advance.

I just installed a new Lochinvar CBN135, and all is working well except my customer is very annoyed with the noise from the powervent kit. "100 decibels" This is the second powervent kit, the first was noisy, and the motor gave off a toxic smell. The new one is quieter, & does not smell, but is still over a hundred decibels. My customer wants me to rip the whole thing out and install something else. Lochinvar techs cannot tell me what the decibels should be, & Fasco. (makes the powervent kit for Lochinvar), will only talk to Lochinvar.

 Is anyone else having this sort of problem?

furnacefigher15

Venting

Are you able to vent into a brick or b-vent chimney?



If not, what kind of discharge pressure do you have?



What voltage to the motor?



100 decibels is a lot. Continual exposure will lead to hearing loss.



Is the noise inside of outside of the house?



How long is the flue run?

BoilerBoy

Noisy

Thanks for your input. The noise is coming from the blower itself, inside. I have two 45 deg ells & 1 -90 in 3" pvc. I have not exceeded the equivalent length of 26'next as recommend in the manual. I ran it for a couple of minutes without the flue attached, and got the name howl.

To vent up the chimney, I would need to co vent with an atmospheric water heater, & the Lochinvar techs say not to co-vent this boiler.

BoilerBoy

noisy

Sorry, voltage is 115v. I did not measure discharge pressure, but it feels more than adequate. Thanks

furnacefigher15

Run it alone

Next step I would take is to physically remove the power vent unit, and run it by itself with no piping connected to it.



If it is still noisy, then its a flaw in the power vent unit.



If its quiet, then maybe the boiler is overly restrictive for some reason.

BoilerBoy

Noisy Powervent

That is a great idea! It has to be, because I had the same idea! ;0) Great minds think alike I guess.   I tried it today and it is slightly noisier off the boiler, than on. Not sure why. After trying that & a few other ideas, I am convinced the current blower system cannot be quieted, we shall see what the Lochinvar engineers have to say on Tues. I am now reconsidering running a stainless liner up the chimney next to the 4" water heater liner. I dismissed the idea before, when the power vent option was discovered. If only I new then what I know now. ;0)  The reason I did not want to do the chimney liner, is it looks like a 50/50 chance for success. There are a lot of mortar hooks in there, and a slight dog leg. Plus I thought it would cost my customer less money to power vent.

We shall see. Thanks for your input. Let me know if you can see something I am missing.

furnacefigher15

Noisier off than on?

I would look at the motor on the venter kit, and see if it has a bad bearing.



Replaced a 25 hp motor on an air handler, and the new one was noisier than sin. Asked the motor supplier what the trouble could be, I suspected a bearing, but they ruled it out.



A day later, I replaced the motor with another from a different supplier, and the noise went away.



I returned the original replacement for a refund, and explained the defect and my dissatisfaction with the denial of a bum motor possibility. Turned out I was right the motor had a bad bearing.



Might be worth bringing the kit to a local motor specialty shop, who has the ability to test it, and see what they think.