What do you think of Ruud furnaces? My Carrier gas furnace is 26 years old and am thinking of replacing it. Are the new furnaces really that efficient that it would save me a lot of money or not? I live in Iowa..so we can really have some cold winters.

A lot depends on what model vs what brand of furnace you get. My dad did HVAC for a few years and he saw a lot of good and not so good. It seems that the cheap units they install in new houses last about 10-15 years and a better quality one will last 25+. My grandmothers house is only 12 years old and I have had to replace the ignitor 3 times and the heat exchanger is starting to rust. This unit is a Rudd and it was installed by the builder. My other grandma has a Rudd that she had installed after her old one died and it is 22 years old and running fine. I would look for a system that is common so parts will be cheap and plentiful. You should shop around for sure. Here in Oregon if I install a 90% or better furnace I can get a tax break and with the cost of fuel here it would pay off. If gas is cheap there and you don’t get a big tax break it may not be worth it. Another thing to remember is if you are going to move before the investment pays off and you cannot make it a selling point you will not save a thing. Just my opinion.

A few questions for you:

  • 1- what type of heat do you have? (gas furnace, oil furnace, heat pump, dual fuel)
  • 2- have you changed the filter(s) lately?
  • 3-has it just started blowing cool air, or has it been this way for a while?
  • 4-what climate do you live in?
  • 5-what temperature is your thermostat set on?
  • 6-does the fan run all of the time, or intermittently?
  • 7- how old is your heating system?

General observations:

  • 1-heat pumps generally produce lower temperature air than gas or oil furnaces;
  • 2- dirty filters slow the air flow rate; if air flow rate (cfm’s) is too low, your high-limit switch may need to be reset
  • 3-if it has not heated in a long time, you may not have the thermostat set on heat; see #6
  • 4-outside air temperature may affect the air temperature, as some local codes require outside air to be mixed with return air to help air quality inside
  • 5- does the system ever satisfy (reach the setpoint of you thermostat)?
  • 6-if fan mode is set to “ON”, fan never shuts off; during the time that your furnace is not calling for heat, this will circulate the air thru your house, cleaning it as it passes thru your filter
  • 7-if your system is fairly new, several safety switches may be installed, such as high temperature limit switches, blocked vent switches, pressure switches (high and low), outside air temperature switches, etc. older systems may not have had these options available.

Ready to call a contractor? if you check these items first and don’t find a problem, call a contractor to thoroughly troubleshoot your system. you may think it is a waste of money, but one faulty safety switch could cause many problems, even a fire! if you are able to be there when the contractor is working, watch what they do; you may be able to do many of the same things next time you have a problem, and save some $$!

Concerning cleaning the ductwork, it can do some good; this is a job for a QUALIFIED, CERTIFIED duct cleaning agency. old dust, spores and moisture trapped in a duct can cause many health problems, as well as cause problems in your house.

This is a gas furnace, with a washable filter that we’ve had a more than 5 years. I think it’s been working like this for quite a few years now, and we live in the SF Bay Area where we are enjoying high 30’s at night and low 70’s right now. We turn it off at night and have it set to 69 in the days. It comes on every so often but otherwise it’s quiet with no fan blowing. The furnace is about 10-15 years old and the ductwork is 45+.

I suggest starting off by turning off the power to your furnace. Then remove the cover from the furnace- may be two panels or just one. Take a good look around inside the controls and fan area; yo uwill probably see some small switches that have a red button in the middle. If you are sure the power is off, push each of the buttons in; if one has a small resistance or makes a barely perceivable ckick, you have found the problem. There may be several of these safety switches in your furnace; they are general located on the flat metal panel behind the controls on the firebox, and on the side of the fire tube area. One should be an high heat control, the one near the tubes is a flame rollout switch, etc. A high heat switch will kick out when you don’t have enough airflow (dirty filter or coil); a flame rollout kicks when there is blowback or backdraft (colgged vent pipe or chimney, or a hole in the heat exchanger allowing the air from the blower to enter the combustion chamber).. If any of these kick again after resetting, call a contractor to analyze your system, as you have a bigger problem than most homeowners can handle.

Mind if I pop in my own question/problem with a furnace? I have noticed within the last two weeks or so that as the gas furnace kicks on to start heating there is a consistent intermittent rumbling purr (worst description ever). I think I’ve even heard it from the outside. Everything seems to be working properly other than that. Does this sound like a common thing and is it something to worry about? Thanks.

I’m going to climb up there within the next couple of days to see if I can identify if this is coming from a mechanical part or if there is some sort of vibration created on the plywood or ducts.

Sounds like you may be describing a delayed ignition. If it is only when it starts, and stops rumbling after the heater is on, then that is what it sounds like. A delayed ignition occurs when too much gas is present before it combusts, causing the rumbling, or it can even sounds like the whole unit is going to blow up, then all the burners ( and gas flowing thru them) are combusting completely, and it sounds normal.

A delayed ignition is frequently caused by something totally common such as clogged orifice(s). There is a particular little spider that likes to nest in these tiny little orifices, and they build webs right in side of them. The result is gas being under very low pressure, cannot flow thru the orifice. I won’t go into much more detail, but you can try to use a pipe cleaner, remove all of the orifices and clean em out. Run the pipe cleaner even if they don’t look clogged. If you don’t feel comfortable doing this, as someone else said, call a qualified technician.