Posted on: 17 March 2020
If your furnace is a high-efficiency furnace, it creates condensation as it operates. When this system has a malfunction, your furnace may shut down and not start up again. What makes the problem frustrating is that the furnace may start again, only to shut down intermittently. If your furnace won't start or if it keeps shutting off, call a furnace repair company to figure out what's wrong so your furnace isn't damaged. Here are some possible causes of a condensation system malfunction.
Overflowing Drain Pan Or Clogged Hose
When condensation collects in the furnace, it rolls into a drain pan to collect, and then it drains out through a hose. If water doesn't drain out as it should, the water in the pan builds and overflows. If the furnace gets wet, it could be damaged, so it shuts down to protect itself. The repair technician will fix the problem with the water spillage and reset your furnace to get it working again. One thing that can cause the pan to overflow is when the drain hose gets clogged.
The drain hose can get clogged with dust, mold, or even ice if the hose is in an area that reaches freezing temperatures. A clogged hose causes water to spill over the pan and shut down the furnace. The repair service can clean out the hose or thaw the ice so there is nothing in it that interferes with proper drainage.
Bad Pump Or Stuck Switch
Some drain hoses empty by gravity alone. Others need a pump to empty water from the drain pan. If the pump malfunctions, water won't drain since the hose isn't lower than the pan. It might be possible to repair the pump, but if not, the furnace repair company might have to replace the pump so the condensation drains properly again.
The float switch is inside the condensation drain pan with the pump. If the level of water gets high in the pan, the float switch moves to the up position and this shuts down your furnace so water won't overflow the pan and cause water damage. When the water level drops, the float switch moves to the down position to allow the furnace to operate.
If the float switch gets stuck in the up position even after the water drops, your furnace won't come back on. There could be debris stuck in the switch, or the switch might be damaged.
The water that drains from your furnace is acidic, so it can cause the parts to wear down over time and need to be replaced. The furnace repair technician will examine all the possible causes of the malfunction and then make repairs that ensure condensation can drain freely from your furnace.