Question for HVAC people out there - Harley Forum

shovelmike · #1 10-12-2009, 03:43 PM

I had a new furnace and a/c put in my house about 16 mo. ago, Carrier Infinity..multi speed fan etc..high tech-high efficiency SEER 19..and ouch...high price too, almost 10 grand. The thermostat appears to be a small computer that communicates with the rest of the system and reports any faults. In a/c mode everything runs along smoothly....in heat mode the system works great but I keep getting a notation on the screen of the thermostat, "system malfunction-call technician". The first 2 times the company that did the installation came out, cleared the codes, and thought it was a fluke..in early Spring when it occurred again the tech came by, checked the static pressure and said it was too high. He said to get it to function properly I need to have larger ducts installed to the tune of 1,000 to 2,000 dollars.
I don't remember the pressure number he gave me but I need to know how serious this is. Like the rest of you I don't have money to burn. Any insights would be appreciated. Thanks, Sincerely: Shovelmike.

Hammerhead Pat · #2 10-12-2009, 04:35 PM

Sorry I'm no help to you Mike, but I would be curious as too why they didn't figure that out when they were installing/recommending that unit

OH, I know, so they can stick you again for duct work

Mr. Big · #3 10-12-2009, 04:49 PM

I do mostly commercial HVAC and I don't buy much Carrier but I'll give it a shot. Is the system they installed the same size as the one they replaced? Also, when they checked the static pressure, did they tell you a figure and what they thought it should be? You are also welcome to email me directly at stateair@comcast.net

Hammerhead Pat · #4 10-12-2009, 05:36 PM

Looks like Mr. Big is going to be the one to help you but after my response I started thinking. I used to do custom cabinet work and have a garage full of woodworking tools. I have a large dust collector and did some research on building a dust collection system, you know, ductwork along the wall and then tee off to individual machines. The term "static pressure " always came up more than cfm did during my research, so there is probably some validity to what the tech is telling you. Seems like you have the "new " technology in your system but the old technology in your house

Good luck, hopefully Mr. Big can get you going in the right direction.

shovelmike · #5 10-12-2009, 08:17 PM

The furnace they replaced was a York High Efficiency, dual heat exchangers, intake and exhaust through PVC out the back wall of the house. It was about 14 years old so still behind the times compared to this latest one- pushed a lower volume of air. The ductwork is the original stuff they installed when the house was built back in '74...the original setup was a Crane electric furnace with elements....it cost me a fortune to heat with that thing.
The installer of this new one is learning as he goes along...had a heck of a time getting it up and running.....and yeah, I wish they had figured it out up front that the duct work wasn't up to the task.

Micheal · #6 10-12-2009, 10:26 PM

Have you tried running the fan at a lower speed to reduce the air volume to see if you get the same error

unclepsycho · #7 10-12-2009, 11:23 PM

Quote:

Originally Posted by Micheal

Have you tried running the fan at a lower speed to reduce the air volume to see if you get the same error

I was thinking the exact same thing!!!! the fan might be moving too much air??
Mr Big seems to be your best bet,
I am a welder/fabricator working as a carpenter right now....

shovelmike · #8 10-13-2009, 08:55 AM

Quote:

Originally Posted by Micheal

Have you tried running the fan at a lower speed to reduce the air volume to see if you get the same error

It is a multi speed fan but as far as I know it selects the appropriate speed automatically. According to a thread on a HVAC forum I saw in which someone was having a similar issue with a Trane unit when the system senses excessively high static pressure it will reduce fan speed to compensate. I will probably gain some efficiency by allowing the fan to run full speed. The system is doing a great job of heating this house and saving quite a bit of propane and electricity in the process. I just didn't want to be harming anything in the system like overheating the heat exchanger or anything like that, as much as this system cost it's got to last a long time, got better things to spend my money on...like Harleys

The dealer is due to come by later this morning to look at it and give me a price. I'll keep you posted. Thanks. Sincerely: Shovelmike.

texan321 · #9 10-13-2009, 10:48 AM

You know I hate this kind of stuff. You pay a professional to do a job - pay the price - then find out that you have to do more? I would not be happy and would have him explain to me why it is now a problem and why he didn't know this when they put it in - part of being the professional....... I would have a hard time paying any more money and would probably turn him him to the BBB.... but that is just me - I get tired of paying for others mistakes......

DamageInc537 · #10 10-13-2009, 07:02 PM

where are you getting this static pressure reading? is it over the coils, or across the filter? do you know? i am an hvac guy, i do mainly commercial/industrial installs, and not service but i do know some things...