Wiring in a make up air vent for water heater

[jim603]

Good afternoon,

I have a bit of a puzzler, at least for me since this is the first time I've ran into this problem.

The customer currently has installed a Bradford White 40 gallon natural gas powervent water heater and coming off the transformer is wiring for a wall mounted louver/make up air vent. When the unit turns on, the vent opens up and visa versa.

Bradford White and State Select (A.O. Smith) are saying that neither of their units have any type of transformer to wire off of and neither of the companies have any solutions for this problem...

Below are a few pictures of the current set up. I need to replace this unit ASAP and any suggestions would be greatly appreciated.

Also, I cannot drill any new holes into the wall, so the make up air HAS TO COME FROM the louvered wall vent.

(((The double white and the double black wires go to the wall louvered venting unit)))

 

[Mr_David]

I like puzzles

Not sure I understand the question.

The schematic is on the new heater?
Normally there is no provision to connect the powered louvered intake air vent to the new transformer.

"Below are a few pictures of the current set up.
(((The double white and the double black wires go to the wall louvered venting unit))) "

you want to connect the intake air louvers so they open when the unit calls for heat and blower comes on?


The double black and double white wires.
They just spliced the supply line with the louver line with a terminal connector the 3rd line is to blower motor.



The transformer, If I am not mistaken is to reduce the 120volt supply to control the ignition control which operates with 24volts.
Transformer has nothing to do with operating the louvers.
It only serves as a junction point. The same power that feeds the blower motor.
look at the schematic. You can connect the power for the louvers anywhere after the thermostat. .
It is the thermostat that controls the blower.
the Ignition and gas valve module uses the reduced voltage from the transformer is powered up only after the airflow switch closes.

I hope that makes scince

 

[jim603]

David, all of those pictures are of the currently installed, old water heater.

I'm looking for a solution for the new water heater. This louvered system is 120v and activated on the 120v side of the current water heater's transformer. Since neither the new Bradford whites and State Select water heaters apparently have transformers like this old one does, where would I connect the 120v leads to the louvered vent in a new water heater?

 

[Mr_David]

Go online and find a schematic or link to an installation guide for the proposed heater you want to install.
The 120 volt supply to vent DOES NOT require anything to do with the transformer. That was just where they connected the 120 supply to an existing supply of 120V.
when the thermostat called for heat, it closes circuit and sends power to blower and the transformer simultaneously.

The new heater has a blower. you just have to figure out how to connect the power supplying the blower to supply the louver.
Again, transformer is for the ignition controls.

show me a new power vent heater that you want to use and I'll see if I can figure it out for you.
some where there is power going to the blower. You just need to tap into that power, properly. just like turning on 2 lights with the same switch.
You are just turning on 2 motors with the same switch.

 

[spcwaters]

Just tie it into the black and white coming off the blower motor?
When the blower kicks on, the vents will open!

 

[Mr_David]

Just tie it into the black and white coming off the blower motor?
When the blower kicks on, the vents will open!

NOT TRUE!! You need to check a wiring diagram.
I just looked up a BRADFORDWHITE POWER VENT and the power to the motor is a blue wire

They don't make it easy for you to tap into it but with some imagination it can be done.
BUT IT may void any warranty on the heater.

Here is a schematic for a BW Power vent

you can tap into the blue wire anywhere after it comes out of gas control valve for power to intake vent motor.
Connect the common white to common white

 

[spcwaters]

I was just going off the one power vent in the crap pile.

It's got a ground, common white and black hot coming off the motor. I am I plumber, just a guess. (Note the question mark) figured it would start a discussion.

OP figure it out???

 

[jim603]

Yes I figured it out today. I ended up going with a Bradford White. It was my first time ever installing a BW water heater and the power vent install for this application was streamlined! Very easy to tie in the make up air vent. View attachment ImageUploadedByPlumbing Forum1455066016.299242.jpgView attachment ImageUploadedByPlumbing Forum1455066036.208003.jpg

 

[Mr_David]

Very easy to tie in the make up air vent.

Curious. What was your solution?
Was my info helpful or did you figure it out on you own?