Top Ten List for Equipment Failures

Glenn Harrison_2

is on Lennox Complete Heat units, and those love to warp and corrode. Lennox did finally double the thickness of the electode/sensor assemblies, and so they last a reasonable amount of time now. Otherwise, the only direct igntion I see is Hot Surface.

John R. Hall

Your input would be great!

If you could assemble a top ten list of the most common HVAC equipment failures, what would be on that list? Feel free to name as many or as few as you would like. It can be any type of equipment from oil burners to radiant systems to condensing units. Your answers will be a big help into some research I am doing.

If you'd rather e-mail me my address is johnhall@achrnews.com.

In advance, thanks!

Mike Reavis_2

top ten (3) for AC

Being that they are mostly machines that are required to pump 1-refrigerant, and 2-air it is anything that impedes, or causes excessive flow of the two "fluids".

Fouled heat exchanger surfaces are way up there.


Ditto for worn or under-engineered electrical components. The worst example I had of the latter was a group of 480 volt rooftops that were shipped with fan relays rated @ 240 volts. After a year or two they all went "pop". Mike

Kal Row

a big dito from me on all 3

even the new scroll compressors which can handle any refegerant side problem except vacume, will get it's windings fried by bad power from a voltage drop anywhere along the path - one bad contactor or breaker and it's over

these three problems are really all of them - heating or cooling - gas/air/water/energy flow, as in too little or too much, and power issues, is all there is

Dale

TechCART

You may want to look at the appliance mag site, asnews.com where the (Techcart)top ten list of repair problems with solutions are collected, someone in your office is probably a subscriber. On modern WA equip, ignitors, induced draft motors/fans, and ignition controls would lead the list. On AC, contactors, fan motors and capacitors ( if you're not counting dirty filters).

Bill Nye

With out....

..a lot of thought, the things that come to mind are: Lack of maintainance, improper application, improper installation, harsh environment [heat, dust, humidity,etc.], lack of maintainance, Water, anything to do with water, like leaks or water leaking from something else or flooded basement or leaking humidifier etc.

Electrical failure , due to lightning or voltage surges or low voltage like brown outs.

Did I already mention lack of maintainance ? Well it is probably by far the number one cause of premature failure.

S Ebels

Equipment failures?

I'll take that to mean actual failure of a part or component on any HVAC appliance. Not a system failure like Bill was refering too.

Number 1 service call item: Failed ignitor on any gas fired appliance. This would be a common silicone based hot surface ignitor NOT the direct spark type used by Viessmann, Buderus and others.

Number 2 service call item. Failed draft inducer

Number 3 service call item: Plugged condensate drain. Why can't these things be designed to handle to goo from a condensing appliance

Number 4 service call item: Failed A/C condenser contactor. These are either the factory contactor, especially on Janijunk and Goodfornothing or else some misapplied or light duty piece that some so called "technician" installed. I've personally never had a good Square D or Allen Bradley fail in the field.

Number 5 service call item: Failed zone valve. Mainly Honeywell but that's because the only distributor in these parts carries nothing but.

Number 6-10 Any other part that dies a premature death due to lack of and/or poorly done maintenance. Blower motors and heat exchangers due to plugged air filters. Non-firing oil burner due to worn out nozzle and/or plugged fuel filter. Obstructed vents due to not having qualified personnel check out the system annually. etc etc etc etc

John R. Hall

Peas in a pod

Steve -- It's true that equipment failure and incorrect installation/lack of maintenance go hand-in-hand. That's a given for my reading audience. I like to hear all answers because people here have great opinions and I encourage them to say whatever comes to mind -- but I prefer actually equipment malfunctions.

Bill Nye

Sorry John

I used to service mostly oil so, plugged fuel filters would be number one but again lack of maintainance.

Number two electrical components, ignition transformers, then motors, then controls or relays.

Then wear and tear parts like pump couplings and bearing assemblys.

But you know what ? Proper maintainance would ........... never mind I'll shut up.

\"Maine\" doug

Did you say maintainance?

Here is the A coil from a building the realtor said was "Ready to move in to". The only reason you can see the fins is because a gloved finger was rubbed on the dirt to uncover them. By the way did you say maintainance??

Glenn Harrison_2

here's a few

Gas furnaces - thermocouples on older equipment, hot surface ignitors, then inducer motors, ignition controls, other control boards, blower motors. Also heat exchangers are becoming more and more of a problem every year, and the avilability ofgetting replacement heat exchangers has frequently lead to replacing equipment that is under warranty, but the people have to have heat.

A/C's - contactor's and capaitors, then condensor fan motors, and leaking evaporator coils are also becoming a bigger problem every year.

Gas water heaters - Thermocouples, relief valves, and tank failures.

Electric water heaters - Elements, relief valves, thermostats, and tank failures.

Boilers - thermocouples or igniton controls, gas flue dampers, Relief valves, fill valves, zone valves, pump controls/relays, circulators.

Unknown

Do not want to be redundant

so I agree with S Ebels numbers 1 and 2 my

2a if you will Vent Dampers. I find a lot of them jammed open with a jumper on the primary control - that is a NO-NO

3. Faulty ground on electric ignition systems

4. Improper Polarity

5. Integrated Furnace Controls

6. Electronic Fan Timers

7. Dirty gas pilots (this is higher for standing pilot systems water heaters, furnaces and boilers.) Dirty flame rods on rectification systems.

8. Lately heat exchangers failing in less than 10 years.

Used to see a lot of Intermittent Pilot Modules failing but that seems to have died down in recent years.

I will not number this one because it goes without saying it is at the top of my list and has no number it is HIGH CO READINGS ON APPLIANCES that just had a service call in the last few weeks. People do not test!!!

The local handyman who thinks he can fix everything, just drive by his house someday and see waht great work he does. Hey maybe he is too busy fixing everyone elses stuff.

S Ebels

RE: heat exchangers

I'd like to hear from anyone else that is concerned with the high failure rate on newer forced air furnaces.

Specifically, what do you attribute the failures to? Overheating caused by ? or ? or? or maybe ?

Chintzy construction, lightweight materials used in production?

Lack of maintenance. plugged air filters, poor installer setup?

How many of you see new 90% appliances that have failed due to an ancient,inadequate duct system?

My inquiring mind wants to know.

Weezbo

i dont do too much service work anymore...However....

fire eyes primaries,drive couplers suntec pumps,zone valves clohgged condensate lines (or undersized) dirty coils dryers,squirrl cage fans motors belts,cracked fire bok heat exchangers not surgical stainless steel,stack sensor,fan switches,capacitors on small motors and circ pumps,bearings on larger beld driven fans,air filters,dirty coils:) broken key stock or the like on motors larger pumps,impellers,booster pumps,these are som component failures fairly common...system wide failures Freeze ups ,no low oil or low water alarm or priority shut down relay,fire throughout the duct work,oil saturated wood floors,corroded flue pipes,...unbalanced systems,compressor failure ,...uh how i am doing so far?

DaveC

Curious about spark electrodes...

Didn't see any comments about spark electrodes in a direct spark ignition system being a problem. Anyone have experience with warping, burning back, corroding or other failures on these? Also expected lifetime, causes of failure, and environment around them are of interest. Thanks for any experiences on this.

Ranger

Heat Exchanger Morbidity

I would have two say oversized furnaces(input)are the number one cause of demise on a 90% condensing product,scorched-air or otherwise.The condinsate does a number over time.(If you've ever noticed your vehicle's exhaust system seams to last much longer if you consistantly drive some distance daily a opposed to "around town".)
Undersized ductwork(esp.return air)You would be suprised at how many tech's out there do not understand temperature rise.
Overfireing:It's set from the factory,right?
Aggressive Environment:Let's put the furnace in the same room we strip furnature!Or how'bout with the indoor pool!
and lastly lack of filter/E.A.C. maintenance:I have one of those?I certainly would have taken care of that if someone had shown me!:-)

S Ebels

All of those things

The failures you mentioned all point to the FACT that modern heating equipment is less tolerant of marginal or poor conditions than the old stuff. Nearly all of the poorly installed, poorly setup furnaces that I see were done by guys who have been in the trade a long time or by homeowners who haven't got a clue what they are dealing with. The older guys who have failed to stay abreast of operating requirements just slap 'em in like they use to do the standing pilot jobs. Maybe check the gas pressure and Wham, Bam, Thank you Mam out the door they go never looking back. I read somewhere in an industry rag that the average life of a current production 90% furnace is less than 10 years now.

I'll be the first to say that any piece of heating equipment has to be installed correctly. However, it seems to me that modern forced air furnaces are built to run good in a lab under ideal conditions and have no margin for error or other field conditions commonly encountered. I'd like to see the manufacturers state plainly right in the manuals that the warranty is void if..........

1. The furnace is connected to a duct system of at least XXX size, sq." or CFM or whatever they would chose.

2. The furnace is installed in a room containing solvents, cleaners or other chemicals

3.The furnace installtion is not inspected by a code official

4. If the post installtion checklist is not filled out and sent in. They should provide one with each furnace that includes temp rise, gas pressure, etc.

The whole forced air industry seems to be dumbing down their products so that any hack can supposedly install one.
I have news for them. IT'S NOT WORKING!!

Glenn Harrison_2

In my opinion...

Many, but not all furnace manufacturers are making a dirt poor, THHIINN, weak heat exchanger to stay competetive in the new construction market. I also believe the manufacturers that have a "builders" grade model with a lower HX warranty have again deliberatly put a lower quality HX in to keep the price down. I sometimes wonder if they take the chance of losing a long time customer with a unit that they know will prematurely fail to get more new home sales now.

I will also guarantee that a lot of the problem is brand new systems with severly undersized ductwork and filter holders. How's a 100,000 btu furnace with a 1600 CFM drive supposed to last with a 800 - 1000 CFM system connected to it.And then the homeowner assumes the system is sized right and the equipment is good because they payed so much for the house. Then one day 5 to 10 years later they get hit with a bad HX and other not so pleasant realaties.

As far as older systems, I this area has much better older duct systems than newer, depending on the age of course.

Yes I am concerned, but I don't see things changing any time soon, so I try to make sure I'm up on heat exchanger testing procedures, to find them as quickly as possible.

S Ebels

I thought I heard

That Lennox was recalling and/or replacing the Complete Heat units???

Glenn Harrison_2

Yes that is true!!!!!!

I have seen in writing from Lennox that the Complete Heat Program is terminated. This includes the HM61 units made by Polaris. They will have warranty tanks avilable for an undetermined amount of time.

Why this is happening I'm not sure. But there is a class action lawsuit out there against Lennox and the Complete Heat units, however I do not know the details of the suit.

IMO, it's about time!!! These things have to be one of the biggest engineering screw ups of all time!!!

DaveC

Thanks, Glenn...

You mentioned Polaris, but I thought that unit uses a HSI (which I've seen people post in the past had a high failure rate, perhaps attributed to flue gas bypass at the vent terminal)? I know the Munchkin and Ultra use Direct Spark electrodes, and would guess the Veissman and other Euro imports, too. I haven't heard about problems on these, but figured some guys here would have experiences if there were any problems to consider?

Ranger

Yes sir I agree...

...whole-heartedly with what your say'in.I am not sure weither the caliber of the persons entering this field are less than "the old days" or that it (The HVAC/R field) has become so technically advanced that you really have to specialize...Not to sound "old" but when I started it was expected of me to be as proficient as posible in as many aspects as posible.Heating:Scorched-air,hydronics & steam,heat-pumps,Air Conditioning:up to 200 tons,Refrigeration:up to 5 h.p.,DDC controls,pnumatics,VAV's...kinda mind boggeling now that I think of it.It seams like it wasen't that long ago truck stock consisted of a 24v and a milli-volt g.v.,some thermocouples and powerpiles,couple of fan-limits,an aquastat,some oil filters and nozzles,a series 100 coupler,motor mounts,bearing assy.& motor,a V8043 zone valve,a taco power head,a....well it did'nt seam like alot at the time.Anyway,I was fortunate to be able to go out to the York assembly plant in Wichita last year and in the lab there I got to see how thay (and I'm sure other manufactures also) are painstakeing trying to make there equipment so user friendly that mongoloids could install & repair them (no offence to the mentally handicaped)because thay see what's going on thru warranty.I'm just happy right now that the head of our department at the company I work for as shown the owners the benifits of factory training as well as haveing us attend I.S.H. and Wetstock.I will go as far as to say the majority of the warranty component failures I have seen over the years are due to improper
application/installation as oppose to shoddy assembly/materials.And I think it takes a good 5 years to make a good service tech/installer that's worth his/her salt,myself included.

Glenn Harrison_2

You are correct,Jim

the Polaris does use HSI. I just mentioned it to completly answer Steve Ebels question.

And thank you for mentioning the above DI boilers. I have not seen these units in the field yet so I was not aware of their ignition systems.

Ranger

That being the case...

Lennox G14/G21 heat exchangers at the tail pipe weld,and later the secondary heat exchanger.
Hydropulse's,right at "the halves".
York rooftop's from the late 80'S/early 90'S spark electrode gap/"trombone" pilot assembly (and thay always seemed to give you trouble when it rained or snowed)
Any Carrier rooftop heat exchanger over 10 years old.
Any H.S.I.system w/no flame sensor (Weil McLain/Rheem)
Any Carrier rooftop draft inducer assembly more than 2 years old.
Carrier V.V.T.(what revision do y-o-u have)
Home center thermostats and the homeowners that attempt to install them.
Any of the first 90% gas furnaces (many tried,some succeeded)
Rheem/Ruud H.P.switches on the 12 s.e.e.r.product (leakers)
Those confounded Amana boiler/furnace glycol thingies from the early-eighties!
Lockinvar and A.O.Smith Legend H.S.ignitors
I have personally installed the following Brands in the last 20 years:Lennox,Trane,American Standard,Carrier,York,Coleman,
Rheem,Ruud,Comfortmaker,Arcoaire,Heil & Goodman,Weil McLain,Burnham,Hydrotherm & Crown.I honestly can say I have had good luck with all.Admittidly each brand has had there own quarks,some more than others,I like the features in some brands over the others,but if installed correctly
troubles should be few...

Glenn Harrison_2

and don't forget those....

lovely Rheem/Rudd Drum furnace heat exchangers that would crack faster longer and wider than the San Andreas Fault!

S Ebels

Ranger

You hit the nail squarely on the head with that last statement. "If installed correctly, troubles should be few." That is exactly the issue or problem if you will. With the newer furnaces, there is no margin for error if you want to produce rated efficiency and acceptable service life.

The old stuff was made heavy enough to withstand a marginal duct system or other "fudge factors". The efficiency might suffer but the old standing pilot, atmospheric vent jobs would run forever. The new stuff is built, in the interest of efficiency and economical production, just as light as they can make it.

The folks who buy some of the "footballed" brands over the internet are going to pay the price down the road. If the equipment isn't set up properly service life and efficiency will deteriorate quickly. Who gets the bad name? Usually not the manufacture. Instead, it's the poor tech that has to come over and "fix" something that failed every winter. Usually something expensive. I hear comments like "I've had Joe Blow over fixing this thing five different times and it always costs me $$$.$$ everytime. He can't get it right at all! Some service guy he is."

Honest technicians dealing with a marginal product in a less than perfect install are the one's that get the finger pointed at them. Or just get the finger.

There, I've had my little rant for the evening and I can go to bed now.

S Ebels

Jim

In regards to direct spark tpe igniton vs hot surface ignitor, Try to name me one piece of commercial/industrial size equipment that doesn't use direct spark. I can't think of any that use an ignitor.

What does puzzle me about hot surface ignitors is this. The ignitors in a gas dryer seem to last forever. Granted, they make fewer cycles but I can't think of a more rotten environment than a laundry room in which to operate either. I have furnaces that I can count on having to replace an ignitor every stinking year. That is poor performance!

Kal Row

drier ignitors dont last forever...

i stock lots of them for just friends, in fact the life compared to ones in boilers is much lower - they cycle more on driers because modern driers try to protect clothes and cycle the burners more, the worst case is when the outlet run is too long or clogged or the lint screen is clogged – it cycles like crazy – I’v seen 15 second cycles

hot surface igniters are simpler and are really great for outdoor use in windy areas like pool heaters by the beach – where you need continuous ignition because of the wind and the salty moisture would just short out the spark line – unless you have a sealed setup like those on jet engines where they use continuous spark in the rain - or the pretty sealed setup like those on the STA-RITE pool heates

though – I had one such larrs pool heater with a Fenwall control – died in such a way, that, it turned on the gas valve without the igniter, and left it on without checking the flame sense circuit – the whole block smelled from gas – one cigarette – and kaboom!
You get weird failures in a windy, salty environment – Carrier AC, makes residential condensing units they call “costal” designed for just that environment – you cant get a 12eer unit, It’s only available in 10err, because you give up 2 points, in the thickness and coatings of the condenser coils/fins

DaveC

Steve, I'm not familiar with any commercial equipment...

I do notice more residential types of high efficiency boilers using Direct Spark though, and am trying to learn what aspects of the design will provide the best reliability. Hot surface ignitors seem to be a mystery, even to the people who manufacture them. They can fail in so many ways - internally, where the tip joins the wires (excessive heat), or the tip itself (excessive voltage, cycles, oxidation, flue gas bypass).

Kal Row

What is amazing though…

Is that virtually all new domestic gas ovens, use hot surface ignition, in fact it’s in series with the hot wax pellet driven oven valve, that heats up and opens the valve, in apx 30-40 seconds – which by then, the HS igniter is good and hot, and if it brakes, well then the circuit is open and the valve stays closed, and if it shorts, the oven “safety valve” (as they are known), has internal protection from direct 110v – I don’t hear about that many catastrophic failures, though my local appliance parts supplier has the two most popular sizes in boxes on the customer side of the counter, with an open sample taped to each box, and says “help yourself” – so I guess, he sells a lot of them – the worst kind of failure in this system is where the igniter glows but actually has a partially through micro crack and while is still glows, it’s resistance is to high to operate the oven “safety valve”, – a less common failure, but also vexing, is the “lazy valve” failure, the avg appliance repair person just changes both and hits you with 150+tx bill – but will then guarantee it


picture from
http://web.appliance411.com/faq/gas_range_ignition_systems.shtml

DaveC

So the HSI is powered the entire time...

the burner is on?

Kal Row

yup!!

even worse - they cheaped out and most of the new safety valves use a bi-matalic heated strip as the current sensor vlave opener, that if the element doesnt brn out instantly on 110v directly, might bend into the slightly open pos,
though i have found a few that took 110v and opened, yet returnd to good working order afterward - so go figure

DaveC

Here's one from \"Laugh In

> even worse - they cheaped out and most of the new

> safety valves use a bi-matalic heated strip as

> the current sensor vlave opener, that if the

> element doesnt brn out instantly on 110v

> directly, might bend into the slightly open

> pos, though i have found a few that took 110v

> and opened, yet returnd to good working order

> afterward - so go figure

DaveC

Here's one from \"Laugh In\"...

just for you, Kal:

Vedy interestink, vat shtupit!

Kal Row

cud nat haff put eet bezer my-zelf

und u call zat ah zafty vaalve ?

DaveC

Here's one more...

Cause I know you like Australian jokes, too:

A truck driver in Australia sees a man with 3 eyes, no arms, and 1 leg hitchhiking (I don't know how he's doing that, but just go with it, baby) - The driver pulls over, kicks the passenger door open, and yells "Aye, aye, aye - yew look 'armless - hop in!" .:^)

Kal Row

better for our story

from love at first bite when goeorge hamilton as dracula wakes up with a hangover afer having bit a drunk - and says
"vat vaz dat mainiak drrinkking..."

my favorite movie line comes from there - when he is leaving transilvainia and they are throwing stuff at him, he says " you kon boo me now, bot, ven i em gaan, traaansilvainia vil be ahs exxciting ahs buccharrest on a monday night!!!"

DaveC

I think Dan needs...

a special section on this site for some of us dementos to put our musings - somewhere there is at least 1 person reading this and thinking "what the ...."! Hey, HE started it! :^~

Kal Row

what he needs..

is the "too sillay, thess is jjust tooo sillay" modirator from monty python's flying circus that would come in and stop a skit, when it got too silly

DaveC

O.K., now the giant foot from M.P.F.C.....

just came down and squashed us - pppptthhhuppppttttt!

And now for something completely different....

Bob Tonner

Commercial industrial ignition

I have worked extensively on designing ignition systems based on hot surface, and I can tell you that the physical limitations of Silicon Carbide make it virtually impossible to construct a hot surface igniter for 240 volt applications, which is what most commercial systems run on.

Bob Tonner

President

InfinityLab Inc.