About:

We are a local family owned furnace repair service  and   heating contractor business that has been serving the Monterey Peninsula for over 20 years.

HVAC CONTRACTOR Lic# 706690

CONSOLIDATED

box 588

Monterey, Ca. 93942

(831) 372-2803

Here are some common mistakes I see repeated that shorten furnace life and a few insights and  stories.

Inducer blowers and fan motors require oiling and maintenance. WD40 is not oil. It washes the oil out and makes bearings fail prematurely. Motor bearings require oiling with a light machine oil. Zoom oil or 3-in-one oil. On belt driven blowers there are pillow blocks that hold the blower wheel shaft that also require lubrication. On one occasion I had to replace a blower shaft that was 90% worn through.

Gas piping should have a sediment trap or drip leg (drip leg is a term carried over from the days of steam boilers) just before the furnace. After the PG&E explosion in San Bruno crews have been replacing sections of gas line. Sand or rust knocked loose by a back hoe can clog a gas valve or pilot light. Sediment traps have always been recommended by the American Gas Association (AGA) and the Canadian Gas Association (CGA). The manufacturers installation instructions show a detail if how these are to be constructed. I am amazed at how many furnaces either have no sediment trap or have it improperly constructed.

On smaller furnaces and residential furnaces the blower is direct driven. The blower wheel is mounted directly on the motor shaft. The return air is drawn across the motor windings to provide cooling. On many occasions I have seen the openings in the motor housing caked with dust and completely plugged. Dust is a pretty good insulator also. This build up causes the motor to run too hot and shortens the life of the bearings and windings.

I get calls where people have just changed the filter and now the furnace won’t start. The most common problem is the blower door safety switch. When the blower door is removed a safety switch is opened that was held closed by the blower door. The purpose is to kill the power so the motor doesn’t start when servicing the blower catching someones hand in the blower or belt. This also acts as a safety to prevent the main blower from pulling exhaust gasses or fuel gasses out of the furnace. The blower door needs to be securely attached to hold the switch down for the furnace to operate.

Here’s an easy one. Sometimes people will un plug the furnace to use the outlet in the summer usually for a re-chargable vacuum cleaner and forget to plug it back in. When winter comes the furnace won’t start. Find me a furnace repair man is what they say next but a little investigation would have helped.

On one find a furnace repair man call I saw a blower door on the burner side of the furnace and the louvered door on the blower side.

On a few find me a heater repair man calls the furnace had been on during the floor sanding which plugged the filter with sanding dust.

The best find a heater repair man call was after a remodel in which the attic access had been sheet rocked over leaving no access to the attic mounted furnace. We had to cut a hole in the dry wall and frame in a door for access. The furnace repair was simple after creating an access.

A word about Carbon monoxide detectors. When the new California law required carbon monoxide detectors in all rental property I received a call from a landloard. He had put CO detectors in all his units and one was sounding off. When I inspected the furnace I found a hole in the back side of the heat exchanger. The hole was smaller than the head of a pin. Pretty impressive for an inexpensive carbon monoxide detector.

Furnaces are like automobiles. They require maintenance. Cars that receive regular tune ups and oil changes are operational for a long time and maintain their efficiency in the form of miles per gallon. Furnaces are amazingly tough. Many go for years with no maintenance. The drop in efficiency goes un noticed because it doesn’t show up in increased stops at the gas station. The PG&E bill just increases but no extra checks are written like the extra stops to the gas station. The PG&E checks are just larger amounts.  Regular maintenance not only can extend their life but the efficiency as well.

Natural gas has impurities. The primary one is sulfur. The sulfur plates out on surfaces and acts as insulation. When it builds up on a sensor the common problem is an intermittent operation. This not only causes fatigue of the components but wreaks havoc with efficiency. Cleaning the sensors is a critical part of a furnace service.

Here is another furnace service man question. Why does my furnace take longer to come on when it is cold? Actually it doesn’t. The start sequence starts as soon as there is a call for heat from the thermostat. The blower takes longer to come on because in older furnaces there is a second thermostat that controls the blower. A cold furnace takes longer to heat up than a warmer one.

What about furnace efficiency? Determining differences in furnace efficiency is not as simple as SEER or COP. SEER is seasonal energy efficiency rating and COP is coefficient of performance. These are theoretical ratings. For a better understanding let’s dig a little deeper into real world usage. The fastest way to get an understanding is to look at some examples.

Let’s look at the efficiency difference between replacing a 70% efficient standing pilot with a 80% efficient pilotless furnace. Let’s assume the furnace is in a vacation home in Monterey that is only used in August so the furnace is never turned on. The standing pilot consumes gas 24 hours a day and the pilotless furnace consumes zero.  The difference in efficiency is infinite.

So from a percentage basis based on energy savings the switch to a pilotless furnace makes sense but the return on investment makes little sense. A better solution would be to turn off the pilot on the existing furnace. This option not only has an infinite energy savings return but an infinite return on investment assuming you could turn off the pilot yourself.

If you look at it from an SEER or COP it would appear to have some energy savings by installing a 95% efficient condensing furnace rather than the 80% efficient pilotless furnace. As you can see the energy savings would be zero and the return on investment would be even worse.

Now let’s take the same house with the existing 70% efficient furnace and locate it in Alaska with 365 day per year occupancy. Now what was the best option (turning off the pilot) becomes the worst and most expensive when you consider the cost of frozen water pipes that have burst and the water damage when they thaw.  What was the worst option becomes the best.

Most cases fall somewhere between these two extremes with many variables to be considered. Occupancy, Insulation, tiered natural gas rates or propane seasonal rates, property re sale value, maintenance costs, installation costs, and purpose are all factors.