HVAC Question - HELP!!!

[wes0778]

In anticipation of today's ice storm (thank goodness at our house it was not as bad as predicted!) I bought a 1200 watt generator to, if needed, power the natural gas fired central heating system at my son's house. The Coleman system is a 1995, 120VAC system that has no pilot light. To be sure we could count on it, I cut the furnace loose from the house power and hooked it up to the generator. When I turned it on it loaded the little generator, but according to the voltage meter on the generator it held 120 volts. The system ran about 30 seconds and I heard the generator unload. My 1st thought was it tripped the breaker on the generator, but that was not the case. I checked the furnace and the green LED, on the circuit board, was flashing rapidly. There is no code listed for that! I turned the power off to the furnace, waited about 15 seconds and turned it back on. The Green LED came on solid and that the little, what I think is called a purge fan, came on and ran about 20, or so, seconds. I heard the generator load up a little because of what I suspect was the ignitor coming on. This lasted about 5 seconds and then a click which I suspected was the gas valve being activated. With that every stopped and the green LED went to flashing rapidly again. I repeated this a couple of times with the same results. I thought well maybe the generator is not able to keep up and the voltage is dropping too low. It seems just the opposite to be the case. With the click that shuts down the furnace the volt meter on the generator "Jumps" up to about 130 or so.

Any Ideas?

I have not been able to find a tag that tells me what wattage the furnace should require.

I would have thought starting the air handler fan would be the largest hurdle, but I have a similar fan from a long since dead system from our house, which I use as a shop fan in the summer. The little generator starts and runs it just fine.

[Pam]

As I understand it your generator is going to be just big enough to run the fans. as there is no pilot lite there is a spark/ignition sensor.

 

So you are hearing the small fan come on which starts the draft up the chiminy, Once the system senses the draft it starts the ignition, and you hear the gas valve open. The kicker is the flame sensor (located in the burners usually white porcelin with a single wire) If it does not sense the flame the furnace shuts down

 

Find the flame sensor and pull it out and use some steel wool on it and clean it up and it should fire up.

 

Happens to my furnace a couple of times a winter.

 

I am noe expert but that is my take on it and a furnace is a major house hold appliance around my end of the world

 

frank

[Guest tx2sturgis]

Oh...at your sons house....ok...

 

Couple of general observations here Wes.

 

First, it seems like the control unit for the furnace is seeing something it doesnt like....duh.

 

Maybe its the higher than normal voltage, or maybe its a possible ground problem. I'm no expert of HVAC, and havent used, or relied on, central heating/cooling for over 15 years.

 

It seems like your buying an undersized genset, since units that are that small have little reserve when it comes to running a house sized central unit.

 

More to the point:

 

Instead of relying on an unreliable generator, why not opt for a secondary heat source?

 

Wood, kerosene, propane...all have advantages when temporarily heating a house during a power outage, and you can instead use that noisy, inefficient generator to power the food fridge/freezer, some lights, and a radio or tv.

 

Generators are terribly inefficient, and some are noisy as hell. For the same dollars you will be spending on gas to run the genset, and then natural gas, heating oil, or propane fuel to feed the large central unit, you can provide much more thermal BTU's in heating directly, say with a couple of portable propane heaters. Propane, for instance, is clean burning, heats efficiently and quietly, and stores for MUCH longer than gasoline.

 

A couple of propane heaters, (or kerosene heaters if you can find GOOD kerosene locally, and dont mind the smell) will keep all but the largest home livable for days on a few inexpensive refills. If you have the desire, the funds, the expertise, and the location, then installing a backup natural gas or propane wall furnace is a viable option.

 

Most Americans are 'sold' on central heating/cooling systems, but I am not. And running a noisy, inefficient, and maintenance intensive generator just to keep an inefficient central unit running seems unproductive to me.

 

 

 

 

 

 

[kevin-vic-b.c.]

I have found over the years... I have 20 years in the heating industry.... that the polarity of the power will cause an issue with modern furnaces. Check polarity... ensure the gas is turned on. If you have a standard say 75,000 btu unit it will only pull maybe 6 amps 120V on full run. The rapid flashing of the LED is normally either ready to fire (heart beat flashing) or you have fried the main control.... back to the polarity thing. The rest of the start-up you describe is normal.... inducer fan on.... igniter on then the click should be the gas valve opening... some manufacturers get the blower fan to start and run for 30 seconds as well.

 

Check gas manifold pressure... should be around 3.5" wc when gas valve opens. 3-5 seconds before going to flame failure lock-out. Turning power off then back on resets the control and it will restart the cycle. It is difficult from so far away but those are my best guesses from here.

 

Kevin

[Eddie]

Reverse the polarity, if it is a mid 90's Coleman it was manufactured by York. Im a Luxaire dealer which is also York and I also sold and installed Coleman stuff before Goodman bought them out.

1200 watts is pushing it, but should run it. Inducer motor will run , pressure switch will make but when its time for the hot surface ignitor to come on it will shut down because of the polarity. Just switch the black and white wires around and you should be good.

[wes0778]

Thanks for the responses!!!

I forgot to mention that when hooked back to the "house power" the system worked perfectly.

On the polarity issue, I made sure the generator was the same as the house, black (hot) to black, White(neutral) to white and bare(ground) to ground.

Thank goodness so far we have not lost commercial power.

 

Anybody want a deal on a 1200 watt (Wally World) generator with only an hour or so in the clock?

[Condor]

The only difference between yours and mine is I have a pilot light.... my heater is ancient.... When we loose power I just unplug it from from the wall and plug it into the generator, and it's always been enough amps to start the blower and heat the house. I've used everything from 400watt to 2000watt gensets.. All Hondas. Never a problem. Like already been mentioned it could be polarity. Another thing that comes to mind is what the genset is putting out in a current syne wave. It may be incompatable with the newer PC circutry???

[Flyinfool]

Did you ever check to see if the generator is wired with the correct polarity? I've seen them wired bass ackwards.

 

Some generators do not output a clean sine wave power, some modern electronics will only work with a clean sine wave power source.

 

On your generator, you said it is a 1200 watt, is that the peak rating or the continuous rating. In just perusing the Wally world web site I did find 1 generator that is 1200W PEAK and 1000w continuous. That is a little small for your furnace. I would recommend for a backup generator at least a 2000 W continuous, to be able to do the furnace and have enough left for a light or two.

 

There should be a nameplate on or in the furnace that will tell you either the watts or amps that are required.

You always want a generator that will provide the needed power at around 75% of continuous capacity. When you push a cheap generator to its limits the power gets real ugly, and they do not live long. Also the little bit bigger generator may actually use less gas than one that is just barely big enough.

[93 venture]

Resistive Load / Reactive Load

 

Furnace Fan 875-1,200 watts/ 2,200 watts

 

Well Pump (1/2 hp) 150 watts/ 1,950 watts

 

Freezer 800 watts / 2,100 watts

 

You need more generator. I use a 5000 watt coleman and its ok,but sucks lots of gas

[wes0778]

You need more generator. I use a 5000 watt coleman and its ok,but sucks lots of gas

 

A little more info; For my house I have a 10,500/7500 generator. It runs the whole house, although I hear it protest when the wife fires up the 1250 Watt microwave.

The 1200 Watt was suppose to be a "get-by" measure, for my son's house. In bad weather he comes to our house (Those that have met him will understand). So, really all I was trying to do was keep the pipes at his house from freezing in case of a power outage. The 'fridge really doesn't matter, he eats at our house:Laugh:.

[CrazyHorse]

I have the same crap furnace from 1995. I looked thru mine and the instructions but nothing told you what amps it used. The only thing I did see in the brain control literature was the the the ignitor could use up to 5 amps or 600 watts starting up to 1800 degrees. I calculated the small blower at start probably 120 watts while the big blower Im guessing would be around 600-800 watts . I don't believe your generator is going to be able to handle that. These really are crap cheap furnaces, I guess. I have been getting estimates to replace mine a couple of guys actually laughed when they looked mine over couldn't believe these were installed in houses.

[CrazyHorse]

In anticipation of today's ice storm (thank goodness at our house it was not as bad as predicted!) I bought a 1200 watt generator to, if needed, power the natural gas fired central heating system at my son's house. The Coleman system is a 1995, 120VAC system that has no pilot light. To be sure we could count on it, I cut the furnace loose from the house power and hooked it up to the generator. When I turned it on it loaded the little generator, but according to the voltage meter on the generator it held 120 volts. The system ran about 30 seconds and I heard the generator unload. My 1st thought was it tripped the breaker on the generator, but that was not the case. I checked the furnace and the green LED, on the circuit board, was flashing rapidly. There is no code listed for that! I turned the power off to the furnace, waited about 15 seconds and turned it back on. The Green LED came on solid and that the little, what I think is called a purge fan, came on and ran about 20, or so, seconds. I heard the generator load up a little because of what I suspect was the ignitor coming on. This lasted about 5 seconds and then a click which I suspected was the gas valve being activated. With that every stopped and the green LED went to flashing rapidly again. I repeated this a couple of times with the same results. I thought well maybe the generator is not able to keep up and the voltage is dropping too low. It seems just the opposite to be the case. With the click that shuts down the furnace the volt meter on the generator "Jumps" up to about 130 or so.

Any Ideas?

I have not been able to find a tag that tells me what wattage the furnace should require.

I would have thought starting the air handler fan would be the largest hurdle, but I have a similar fan from a long since dead system from our house, which I use as a shop fan in the summer. The little generator starts and runs it just fine.

 

 

Having fixed mine several times it sounds like either the ignitor is not working ie broken or your not able to get the ignitor heated up to proper temp due to not enough watts and then it shuts the gas valve off and then the furnace wont start. With the furnace now not starting it there now is no load on the generator so voltage jumps up for a second. Correct me if I'm wrong electrical gurus. See above post.

[bkuhr]

Little off topic, but just read in local paper that install of new, or repair of existing HVAC requires KENTUCKY STATE permit and inspection. Also only people that can get the permit are HVAC liscense holders. This is required in ALL KY counties including those that do not have or require building permits, or have a process for issuing permits, or have inspectors.

 

BIG BROTHER watching out for us. No mention of what the permit and inspection fees are.

 

just pulled the article off net and it had link with more info

 

1.) Law now requires permit for new HVAC units

Author: ROBYN L. MINOR, The Daily News, rminor@bgdailynews.com/783-3249

Publish Date: January 10, 2011

Word Count: 446

Document ID: 134AD4F6B2EB1C48

Word is slowly spreading about a new state law that requires contractors to obtain a permit and an inspection for the installation of new heating and cooling units.

The permit requirement and inspection covers the entire state, even in counties that don’t require building permits.

“We’ve had all kinds of inquiries about the new permits – in fact, I had a call this morning from a builder,” said Ray Watt,

 

Daily News (Bowling Green, KY)

Law now requires permit for new HVAC units

ROBYN L. MINOR, The Daily News, rminor@bgdailynews.com/783-3249

Published: January 10, 2011

Word is slowly spreading about a new state law that requires contractors to obtain a permit and an inspection for the installation of new heating and cooling units.

The permit requirement and inspection covers the entire state, even in counties that don’t require building permits.

“We’ve had all kinds of inquiries about the new permits – in fact, I had a call this morning from a builder,” said Ray Watt, Warren County building inspector.

Contractors obtain the new permits from a state office.

“I think this is a great idea and something that should have been done 20 years ago,” Watt said. “Heat and air problems are probably responsible for the biggest waste of energy we see. (Tennessee Valley Authority) tried to push for this several years ago, but could never get the inspections enforced.

“I’d say 90 percent of the heat and cooling pumps installed around here are done so improperly. This is going to be great if the state does what it says it will.”

Watt said he has a meeting Tuesday with state officials to learn more about the new law.

Permits for a single- or two-family dwelling are $75, with $50 for an additional system. Multifamily units are $75 plus $25 for each additional unit. Commercial permits will be based on the overall cost of the project.

Roger Banks, field manager for the state’s heating and cooling division, said there have been several applications made statewide.

But the state’s permitting software is not fully functional yet, so an exact number isn’t available.

Banks said the HVAC master contractor, who already is required to be licensed, is responsible for applying for the permit and obtaining an inspection. If a homeowner is installing the system, then he or she is responsible for the same. Inspections might not be required for replacement installations.

In Bowling Green, contractors may apply at Department of Housing, Buildings and Construction at 1018 Center St. or in Glasgow at 100 B Reynolds Road. Applications can be found on the state’s website at http://www.dhbc.ky.gov/hvac/fap and then mailed to 101 Sea Hero Road, Suite 100, Frankfort, KY 40601.

The HBC is in charge of policing the new law, which went into effect Jan. 1. Any contractor caught without a permit may be fined $100 for the first offense, $250 for the second and $500 for all others or potentially face an administrative hearing.

Banks reminds contractors that it’s a misdemeanor to perform HVAC work without a license. It could mean a $500 fine and jail time.

— To check if a contractor is licensed, go to https://hbc.ky.gov/licensing/electrical/license_lookup.asp

To reach inspectors for the Bowling Green area, call Ernest Bates at 270-499-2927 or Timothy England at 270-404-3583. The HVAC Division in Frankfort can be reached at 502-573-0395.

Copyright 2011 News Publishing LLC (Bowling Green, KY)

Edited January 12, 2011 by bkuhr
more info

[Eddie]

Little off topic, but just read in local paper that install of new, or repair of existing HVAC requires KENTUCKY STATE permit and inspection. Also only people that can get the permit are HVAC liscense holders. This is required in ALL KY counties including those that do not have or require building permits, or have a process for issuing permits, or have inspectors.

 

BIG BROTHER watching out for us. No mention of what the permit and inspection fees are.

 

I wouldn't say big brother, I would say thats the state watching out for home owners that think they can do anything. Being an HVAC contractor myself I could sit and tell you some stories of some of the " call my buddy up and bring a case of beer over and install my new furnace stories" . Many people die of C/O every year. Plus it's revenue for all these states like Michigan that are looking for money. Many cities around me are really cracking down on any work being done without a permit.

 

Coleman was a decent product on the lower side price wise in and around 2004