Regular Furnace Servicing?

[TromboneAl]

Yesterday our furnace stopped working. When I talked with a HVAC company, they started preparing me for the expense of getting a new furnace, but happily, I was able to fix it myself by just cleaning some carbonized stuff which was apparently inhibiting the lighters. The arrow shows the debris that I cleared:

That furnace is twenty-two years old. I had it serviced once about eight years ago.


Googling suggests: service annually.


What do you think?

 

[travelover]

There really isn't that much to do on a gas furnace. Replace the filter, clean dust and rust out around the burner. If it is condensing type, make sure the drain is open. Probably a good idea to replace the igniters every 5 to 7 years.

 

[SumDay]

We pay $100 a year for annual AC and Furnace check-ups, which also gets us same day service when we have a break down (or we get our $100 back).

DH watches over their shoulder to make sure they aren't showing us parts they brought with them that are "about to wear out". Every part they've preemptively replaced has been on the AC.

It's worth the peace of mind to me, especially the same day service since I would die in the summer without that AC.

YMMV

 

[ERD50]

There really isn't that much to do on a gas furnace. Replace the filter, clean dust and rust out around the burner. If it is condensing type, make sure the drain is open. Probably a good idea to replace the igniters every 5 to 7 years.

+1

Gas furnaces burn very clean, so very little to really maintain. Here's what I suggest:

When you know it is working properly, notice and note the whole start up process, for reference. The exact process depends upon whether you have a standing pilot or some sort of igniter system. But typically after a "call for heat" [edit - GravitySucks correctly pointed out I forgot that first, the draft inducer fan should start up, that should pull in a pressure switch a few seconds later, then....], if igniter, the igniters should start glowing red, after a delay to allow them to heat up the main gas should come on (you'll hear it) and it should take a few seconds for the main gas to ignite.

Note the flame and spread. After another 30 seconds or so, the blower should start. At that point, the flame should not change - if the flame changes, that can indicate a cracked/rusted (rust might be an issue for you?) heat exchanger, blowing air into the combustion chamber, which could cause flame roll-out or some exhaust into the room.

I would make a point of watching ours start up at the start of the season, and whenever I thought about it - every few weeks I'd say.

Our new furnace is so sealed up, I'm not sure there's much I can even watch for. I need to check youtube for how to monitor these newer condensing units.

If yours has one of those glow igniters, a spare would be advised, maybe replace at this time as travelover suggests. If it is a standing pilot, keep a spare thermocouple on hand.

-ERD50

 

[ERD50]

We pay $100 a year for annual AC and Furnace check-ups, which also gets us same day service when we have a break down (or we get our $100 back).

DH watches over their shoulder to make sure they aren't showing us parts they brought with them that are "about to wear out". Every part they've preemptively replaced has been on the AC.

It's worth the peace of mind to me, especially the same day service since I would die in the summer without that AC.

YMMV

I wonder how much same-day service would cost (if anything) w/o a contract?

A few years back, our A/C iced up and quit, and I had an event to attend and would be gone for the day (DW was home). I called a place that I never dealt with before and, they were out that morning, had it fixed in no time. Maybe I had one other call that I'm forgetting about, but that's in 40 years of home ownership. $100/year would buy some real "bribe money" to get them out that day, if needed at all.

As you say, YMMV. We use our A/C a few weeks at a time, a few times during the year, it's not on all summer. But when we need it, we need it. If I were down South or West, and it was on regularly for months and months, so a much higher chance of failure, I might feel differently.

But that would be for the A/C. For a gas furnace, there's almost nothing (other than the igniter maybe) that can be predicted to fail from an annual service check. Do the visual I mentioned, and you will be able to notice any changes that might indicate a pending problem, but most are of the "working today - not working tomorrow" type failures that cannot be predicted.


-ERD50

 

[GravitySucks]

+1

Gas furnaces burn very clean, so very little to really maintain. Here's what I suggest:

When you know it is working properly, notice and note the whole start up process, for reference. The exact process depends upon whether you have a standing pilot or some sort of igniter system. But typically after a "call for heat", if igniter, the igniters should start glowing red, after a delay to allow them to heat up the main gas should come on (you'll hear it) and it should take a few seconds for the main gas to ignite.


-ERD50

On all the gas furnaces I have had the proceeding is true, but first the induction fan (small blower connected to the exhaust vent) comes on triggering a pressure switch.

My furnace died Monday. Trouble shooting got me to believe the controller board went bad. Expensive part so I called a pro to verify. Sometimes I hate being right.

 

[imoldernu]

Thanks for the reminder... we just had Stanley Steemer here for our 15 year carpet cleaning, so I'll do my 15 year furnace check and be ready for the next 15 years.


While we're on service... the only thing we've had to replace since moving in, was a hot water heater. I almost fell over. the last one we had to buy was a long time ago, and I remember hating to pay the $140 (including installation). As i recall it was glass lined and had a 30 year guarantee. Imagine my horror when we had to pay $500 for a basic water heater with a 6 year warranty. And installation on top of that!.

Life goes on....

 

[ERD50]

On all the gas furnaces I have had the proceeding is true, but first the induction fan (small blower connected to the exhaust vent) comes on triggering a pressure switch.

My furnace died Monday. Trouble shooting got me to believe the controller board went bad. Expensive part so I called a pro to verify. Sometimes I hate being right.

Ahh yes, good catch, you are right (I'm about ready to turn on the A/C, getting hotter here today, so furnace is a bit distance memory).

Yes, all but very old furnaces have a draft inducer fan, that pulls air in through the heat exchanger, and out the exhaust. It comes on first, and if that pressure switch doesn't sense the drop in pressure on the 'sucking' side, it won't proceed with anything else. [ I was still able to edit my earlier pos, so I did thatt]

So that's a good first trouble-shooting step - did the draft inducer fan turn on, and did the switch activate (bad switch, or maybe something blocking the exhaust, etc).

-ERD50

 

[TromboneAl]

All right. We have the advantage that if the furnace breaks, we can use our wood stove until we can get an appointment for fixing it. IOW, we don't need to fix things before they break. For years, we rarely used the furnace.


>When you know it is working properly, notice and note the whole start up process, for reference.

Great tip, for lots of things.

 

[frayne]

Have my HVAC (all electric) serviced and checked annually for about $75, cheap insurance in my way of thinking.

 

[LOL!]

We never have had annual inspections of our furnaces. One of them did not work for two winters before we really noticed. I tried to fix it per the usual youtube videos, but then had a friend who runs his own HVAC side hustle replace it.

So all those years of not paying for inspections got me a new furnace instead for a slightly lower price.

Most people are mechanically clueless and end up pay way too much for the easy stuff and even more for the hard stuff.

 

[TromboneAl]

I would have felt bad if the guy came ($95 just to look at it), knocked the dirt off, and it worked.


Tomorrow I will take a video of it working normally. Same for the dryer.

 

[Jerry1]

I’ve had the annual inspection a couple times in my life, but I looked at what they did and didn’t see the point. They never seemed to actually do anything. I think the point of knowing the startup cycle is right on. Personally, I think that’s all they did. Watch the cycle and if it worked, they put the cover back on and called it good. Though, I also don’t feel taken advantage of. A service call from a professional is gonna cost $100 bucks just for them to show up. It certainly didn’t hurt to have it looked at by someone, but again, once familiar with the unit, I didn’t see the point.

Oh, and always have a carbon monoxide detector.

 

[ERD50]

I would have felt bad if the guy came ($95 just to look at it), knocked the dirt off, and it worked.


Tomorrow I will take a video of it working normally. Same for the dryer.

He'd probably do more than knock the carbon off. It looks like an igniter, he'd probably replace it. Some of them do age. Depending on design, I think some look for the resistance to increase as they heat up, and use that as feedback to turn the gas on. And that resistance value can change with age. Cleaning helps per some youtube videos I've watched, but a pro is probably just gonna replace it - they don't want to get a call back and a dissatisfied customer if it failed a month later, and they can charge more for a new part anyhow.

And I don't mean to infer that a service call like that is a rip-off, they need to make a buck, and shortcuts just aren't always a professional way to go. But a DIY guy/gal can do it and monitor it and follow up if the first approach didn't work - that just doesn't cut it for a pro. A DIYer can save a lot of money that way, and be prepared in an emergency.

-ERD50

 

[jollystomper]

On the last electric heat pump we bought almost 6 years ago, as a condition of the extended parts warranty, I bought an annual service contract (was $150 for the first 4 years, just went up to $200). This covers 2 maintenance calls a year (fall/winter and spring/summer), warranty service for 5 years, and discounted labor rates on any repair visits.

This did not prevent 2 compressor failures this summer (which I described the joy of in another thread), the first of which I still had to pay $1200 since the 5 year service labor warranty expired end of last year. At least after the 2nd failure they did not charge me anything to install the 3rd compressor and have come out a couple of times free of charge to see how it was operating.

 

[trirod]

When we bought our house 28 years ago, the furnace that was installed would send a whoosh of flame about 6-10 inches out of the front of the furnace every time it lit. As much fun as that was, we figured it would make sense to get a new furnace. Since we thought we were only going to be staying in this house a couple of years we got the cheapest one we could find. I never had the furnace serviced professionally - I would clean out the dust from time to time with a brush and shop vac, and replace the igniter every few years when it went bad. Last year it quit working and after testing everything on it per some YouTube videos I determined the board was bad. Much to my surprise I got a new board on Amazon for $40 or so and it was a 30 minute job to replace.

So I guess not having regular servicing does not seem to have shortened the life of our furnace or made it any more prone to breakdown, and over 28 years I have probably saved enough to buy a whole new furnace.

 

[Bamaman]

Modern gas furnaces and heat pumps are supposed to be "high efficiency", however they're not built nearly has heavy as the old generation HVAC systems. Common problems are small leaks requiring a/c units "rejuiced" with ultra expensive coolants --$200. All a/c units have capacitors to electrically start them, and they are highly problematic and often need replacing. And every HVAC truck carries replacement fan motors for the outside condenser/compressors that cause so much problem. HVAC manufacturers could easily put higher quality components into their units that would stop a large percentage of service calls for just a little $.

I just replaced an A Coil in a very high line heat pump system. Just the part alone was over $1,000 and it was difficult part to find. I told my heating contractor that's the last money I'm spending on my heat pump as I'll be changing over to multi head mini split heat pumps in the future. The HVAC guy said he's already switched to mini splits at his home. Without ductwork, they are so much cheaper to install and much more efficient.

 

[Offgrid Organic Farmer]

We have an old oil-fired boiler that had its jet replaced with NG about ten years ago. We bought the building two years ago. It has not been 'serviced' yet.

The previous owners did a lot of DIY modifications to the system. I am planning on having a tech go over it in detail next Spring, and to remove most of the extra add-on junk in the system.

I could see hiring a service tech to do an 'annual' servicing about every 5 years on average.

 

[yakers]

All a/c units have capacitors to electrically start them, and they are highly problematic and often need replacing.

Would you do this yourself? I had a service call where the technican said the capacitor tested low a bit and wanted to replace it for , I think $200+. I decided to skip it as I have a house warranty AHS which costs $75 a visit +parts my only problem might be not as prompt service. Months later they called and wanted to come out for a $400 service, I declined. I looked on youtube and it looks like 15 minutes and three screws to change and a $15 -$35 part. A capicator does store energy but it doesn't look like rocket science to change.

 

[Alan]

Whether or not you do the servicing of your gas furnace yourself it is good to have a CO monitor/alarm in the vicinity. We have a combined smoke/CO alarm in the corridor outside the room where the furnace is, which is also close to a couple of bedrooms.

My sister and her family had a lucky escape about 10 years ago. She was giving up smoking under a PCP's control which included regular blood gas checks, and when she assured the Dr that she had not been smoking since her last visit he told her that her blood test had elevated CO levels and that she needed to get the boiler checked. CO levels in the house were indeed high due to the gas burner not fully burning the fuel.

She now has a CO monitor in the house.

 

[Winemaker]

I have 3 $180 contracts. One for house, and two for two rental units. Just started them 3 years ago, as I never believed in them. However, since we travel a good deal more, the units would always conk out on the coldest/hottest weeknd/holiday night, when we weren't at home. No overtime or weekend charges, and 15% off parts; and they have a key to the rental basements. For me, $360 for the rentals well worth it, for my own home, $180 keeps the DW happy, and 1200 bottles of wine happy, exclusive of each other.

 

[Walt34]

All a/c units have capacitors to electrically start them, and they are highly problematic and often need replacing.

Would you do this yourself? I had a service call where the technican said the capacitor tested low a bit and wanted to replace it for , I think $200+.

Yikes, that is a huge markup!

A/C capacitors are easy to test if you have an ohmmeter around. Disconnect the wires from the capacitor and make sure it is fully discharged by placing a screwdriver or something across the terminals. Momentarily place the ohmmeter probes on the terminals, it doesn't matter which one. Now reverse polarity on the probes and there should be a spike in the voltage and then it will drop to zero as the capacitor discharges. This happens quickly so watch carefully.

Make sure the A/C is at least turned off, better yet turn off the power to it.

This technique is 40+ years old so if things have changed I'm sure someone will be along to tell me how wrong I am.

 

[travelover]

Yikes, that is a huge markup!

A/C capacitors are easy to test if you have an ohmmeter around. Disconnect the wires from the capacitor and make sure it is fully discharged by placing a screwdriver or something across the terminals. Momentarily place the ohmmeter probes on the terminals, it doesn't matter which one. Now reverse polarity on the probes and there should be a spike in the voltage and then it will drop to zero as the capacitor discharges. This happens quickly so watch carefully.

Make sure the A/C is at least turned off, better yet turn off the power to it.

This technique is 40+ years old so if things have changed I'm sure someone will be along to tell me how wrong I am.

This is a neat tip. Would a digital ohmmeter catch the spike?

 

[Walt34]

This is a neat tip. Would a digital ohmmeter catch the spike?

I would assume so, but I don't really know since I've never tried it. All we had at the time were analog ones.

 

[gauss]

I repair mine (myself) when it breaks. Over the past 19 years, I have replaced:
- blower motor
- igniter
- differential pressure sensor (inducer stage)
- condensate pump(s)

I have developed a sense of confidence/satisfaction on being able to resolve these issues myself.

I don't perform any other type of routine service other than changing the filter.

-gauss