How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site. Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Gaztech Your Own Question
Gaztech, HVAC Technician
Category: HVAC
Satisfied Customers: 475
Experience:  Owner at Gaztech
Type Your HVAC Question Here...
Gaztech is online now
A new question is answered every 9 seconds

I have an air exchanger that works for the rest of the

This answer was rated:

I have an air exchanger that works for the rest of the house, except in the bathroom when it is turned on to eliminate humidity
JA: Did you double-check the thermostat's settings? And what about the filters?
Customer: Yes and yes
JA: Do you plan on doing the work yourself?
Customer: yes
JA: Anything else we should know to help you best?
Customer: no

Welcome to Just Answer, my name is ***** ***** I will do my best to help you with your issue.

If my initial response doesn’t answer your question then let me know and we can continue our conversation.

NOTE: I can only get paid for assisting you if you RATE ANSWER the 5 star rating after you are satisfied with answer.

Are you ready?

Customer: replied 11 months ago.

First thing to check is control wiring behind the switch and at the air exch. for good contact, but In most cases and I just fix the same problem today, is the bathroom control is toast and will need to be replaced.

Customer: replied 11 months ago.
What am I checking for at the air exchanger? The capacitor in front of the blower? I think the switch is ok, checked all the wiring there. I checked the voltage at the capacitor and it was 0. Shouldn't it be reading something

You said it works for the rest of the house so has nothing to do with capacitor, anyways dont forget when you open the door of air exch it cuts the power off

Get it? You said (I have an air exchanger that works for the rest of the house, except in the bathroom )

Customer: replied 11 months ago.
Ok, so what should I be checking for? The switch has 4 wires, the top two are a normally closed switch and then the other 2 feed the timer and are both reading 24 volts

do you have other timer switch it the house ? you could swap one to see if it will work

Customer: replied 11 months ago.
I do not, cannot even find another 4 wire timer switch like this

What brand is the unit?

Customer: replied 11 months ago.
It is a renewaire ev130 model
Customer: replied 11 months ago.
that's a two wire. What do I do with the other two wires in the box?

control comes with wiring instruction, it will say witch two you will use

Customer: replied 11 months ago.
how do I test if it is the switch, I don't want to start throwing money at it and hoping

take defective switch out the wall and take the 2 wires marked PB PB off the control and put them together, it should start the air exch.

Why does it take you so long to reply?

Customer: replied 11 months ago.
Would those be the two that have the 24v constantly when I check them?I am currently at work.

No, it's the other 2, dont make that mistake, if you look at the links I sent you there is a wiring diagram that shows that clearly.

Customer: replied 11 months ago.
the two without power you're saying, yes?The diagram you sent shows a pbl and ptl. My current is both of those put together I believe

Yes, I beleive the control you have is no longer available, so never short out the power R C, put the other 2 together

Customer: replied 11 months ago.
Shorting out the other two did not turn the unit on. Other ideas?

Just to clarify.. if you set the MAIN control ON, does unit work?

Customer: replied 11 months ago.
Sorry, no it does not. I thought it did but that was just the furnace fan blowing. With the switch on, I can hear a faint hum or buzz, but the unit is not on

That changes everything!!!

At this point it could be many different things.

If you open air exch. can you manually spin the blower wheel? is it seized, hard to turn or all free?

Customer: replied 11 months ago.
Spins very freely

Press in door switch to allow power to unit and try spinning it then and see if tension changes, if not try and locate where hum is coming from

Customer: replied 11 months ago.
Ok, now we're getting somewhere. Still spinning pretty freely. Makes more noise when I spin it. There are two blowers that both spin one on top, and one on bottom. There is a metal casing (I assume the motor in between the two) and I'm pretty sure that is the source of the buzzing or humming

There you go!! and that is a common issue with those units,

You can call the number on link I sent you and proceed in getting a replacement blower assembly kit.

We can resume this issue at that for sure.

please dont forget to rate the 5 star rating for me to get credited for walking you through this.

best regards


Customer: replied 11 months ago.
Sounds good. Are those fairly simple to install? Which link? The one directing me to my local rep?

Yes and Yes..

Can you please Rate my assistance so I can get credited for helping you

Best regards


Gaztech and other HVAC Specialists are ready to help you