Air conditioner or heat pump noise diagnosis & cure: HVAC systems can produce a stunning range of noises many of which can help lead quickly to the trouble source and thus can help tell us what repair is needed. This air conditioning repair article discusses the diagnosis and repair of air conditioning compressor noises which range in importance from normal (if annoying squeaks and squeals, to rattling loose bolts and hardware, to shrieking and howling or death-rattles that sometimes (not always) presage costly compressor damage indicating air conditioning compressor or A/C compressors at or near end of their life. In the A/C system noise diagnosis article below we discuss how we approach listening to and interpreting noises coming from an air conditioning or heat pump system. This article discusses how to diagnose & repair air conditioning compressor noises from the compressor/condenser, air handler, duct work, filters, or controls If your air conditioning or heat pump system has lost its cooling capacity or won't start

see REPAIR GUIDE for AIR CONDITIONERS. See HOW to DETERMINE COOLING CAPACITY of air conditioning equipment if the system seems to be working but is inadequate to cool your building. Contact us to suggest text changes and additions and, if you wish, to receive online listing and credit for that contribution. If you hear unusual noise at the air conditioning system, these compressor sounds could indicate the need for a simple service and adjustment requirement. But air conditioner compressor noises might also mean that you face an upcoming costly repair involving replacement of the compressor itself. You should have the system checked promptly by an air conditioning service technician. The following is a list of air conditioning compressor noises and what they may mean about the operation, condition, and remaining life of the cooling system equipment. I have a National comfort Products CPO 2464-B unit which is an air conditioner and gas heating unit combined.

The unit is about 5 years old. The air conditioner had become increasingly noisy. I called the party that installed the unit. After spending $90.00 for a service call I was informed the the external coils were dirty, opening up the unit light was not visible thru the coils.air conditioning unit ratings I was advised to use a garden hose and rinse the coils. parts of a split ac unitI did not have that available so I turned the unit on and using a watering can, poured warm soapy water onto the coils. air conditioning units for busesthis was done several times. the unit now seems to work properly. I did not see this particular problem described on your website. There may be other means of cleaning the coils but this was all I could think of.

- C.A.P., Norristown PA Fujitsu has offered some helpful advice in troubleshooting noises that may be heard at the indoor wall-mounted air handler of a split system air conditioner or heat pump. What's particularly helpful is that Fujitsu points out that some noises that people worry about are actually normal and not an indication of trouble. Here are some other noise or sound diagnostic clues for split system air conditioners & heat pumps Continue reading at NOISES, HVAC SOUND DESCRIPTIONS or select a topic from the More Reading links or topic ARTICLE INDEX shown below. Or see HVAC SYSTEM NOISE DIAGNOSIS FAQs 1982 Mercedes W123 300D Turbo Diesel 1982 W123 Turbo Diesel Recently, my AC started blowing extremely HOT (hotter than the normal heat). No matter what settings I change and which buttons I click, it blows HOT. It blows HOT with all buttons. I also noticed that the climate sensor on the dash that usually "clicks" when I rotate the temperature wheel is not "clicking" anymore and is silent.

Note: for a long time now (years and years), in order to get any of the buttons to work, I usually have to click the defrost button first and then the other buttons will engage and work. Not all the time, but most of the time. I have a newer compressor (less than 2 years) and my blower motor is working and I can hear the compressor engage when I click the AC button (it just blows extremely hot). I checked all the fuses and they seem fine. Coincidentally (or not), this started happening the day after I did two things to my Mercedes: 1) I took apart and replaced the rubber bumper fasteners (mounts) under my air filter housing unit. 2) Replaced the front shock absorbers. Could either of these two things have anything to do with this problem with my AC? Could I have jarred or bumped anything in the same proximity to any AC stuff causing this extreme heat? Many thanks for any suggestions, help and guidance. I've already done a lot of research online, but I just don't know where to begin (aside from taking it to a shop for diagnosis, which is the next step if I get stumped here).

Here's the excellent guide by on repairing it: Mercedes W123 Climate Control Unit v2 Replacement Hopefully he will get a notice of your question and chime in ;-) Mercedes W123 Climate Control Unit v2 Replacement All heat, all the time, is usually a sign that there is an electrical problem. The monovalve is opened (to allow hot coolant to flow to the heater core) by the ground side of the circuit. If you are getting very hot air all the time then the monovalve is seeing a ground at all times. Before anything else, check the connector on top of the monovalve. It is a small black plastic plug that could have been knocked off while you were changing the front shocks or air filter mounts. If the plug is still attached, the problem MAY be in your climate control push button panel or it MAY be in your temperature regulator (silver box behind the glove box). Both can be replaced for units that have been rebuilt. One quick thing to try that may give you some relief in the meantime - if you have not already, try turning the temperature wheel on your dash until it clicks in to the MIN setting.