Question about Mitsubishi MSH12TN Air Conditioner

1 Answer

Have one heatpump condensing unit[muh12tn] with 3 evaporators [msh12tn] in cooling mode on all tstats getting cold from number 1 and 3 evaporators but warm air from number 2 all coils have been cleaned

Posted by on

1 Answer

  • Level 2:

    An expert who has achieved level 2 by getting 100 points

    MVP:

    An expert that gotĀ 5 achievements.

    Governor:

    An expert whose answer gotĀ voted for 20 times.

    Scholar:

    An expert who has written 20 answers of more than 400 characters.

  • Expert
  • 70 Answers

Check and see if they have solenoid valves on each and if they have tx valves or cap tubes to meter refrigerant. txv could be bad, solenoid not opening or even low on freon, Sounds like valve is not opening or dead power head on txv.

Posted on Jun 28, 2009

1 Suggested Answer

6ya6ya
  • 2 Answers

SOURCE: I have freestanding Series 8 dishwasher. Lately during the filling cycle water hammer is occurring. How can this be resolved

Hi,
a 6ya expert can help you resolve that issue over the phone in a minute or two.
best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.
the service is completely free and covers almost anything you can think of (from cars to computers, handyman, and even drones).
click here to download the app (for users in the US for now) and get all the help you need.
goodluck!

Posted on Jan 02, 2017

Add Your Answer

Uploading: 0%

my-video-file.mp4

Complete. Click "Add" to insert your video. Add

×

Loading...
Loading...

Related Questions:

1 Answer

I have a Bonaire split aircondition & heating system. When I use remote controll change mode doesn't work heating mode. Other mode are working properly but heating mode doesn't work.


check the ambient temperature as there is most probably a lock out feature that will not allow reverse cycle to work if the system cannot remove the cold from the evaporator
To understand the system , when in cool mode the outside unit is called the condenser and in effect removes the heat trapped by the evaporating gas in the evaporator to the atmosphere
in the heating mode the roles of the evaporator and the condenser are reversed so that the evaporation of the gas in the now evaporator out side is now compressed in the inside unit and the heat from that compression action is released into the room
read the manual for the unit or talk to an ac specialist and have it explained

Apr 18, 2015 | Heating & Cooling

Tip

Why your unit is freezing up.


To understand why your AC or heat pump is freezing up, it helps to know how your system works.

There are 7 major parts to an AC system, 9 with a heat pump.

1 - Condenser/heat pump (The outdoor unit)
2 - Air Handler (the indoor unit unless the system is a package unit, then all is outside in one system. The air handler is usually found under the home, in an attic, or in a closet.)

In the condenser are the following major parts.

3 - Compressor
4 - Condenser coil
5 - Condenser fan
6 - (HPs only) reversing valve

In the air handler are the following major parts.

7 - Blower motor
8 - Evaporator coil
9 - (HPs only) electric heat strips

Some systems known as "dual fuel systems" use another heat source in place of the heat strips, usually a gas furnace. I will address gas furnaces in another post.

When an air conditioner is operating properly several things are taking place.

1 - The compressor is compressing or "pumping" refrigerant through the system.

2 - through changes in pressure, the refrigerant makes the evaporator coil get very cold, and the condenser coil gets very hot.

3 - The blower motor/fan circulates air across the evaporator coils, as the room temperature air (Also known as "indoor ambient") goes through the cold coil, it exits, cooled approximately 15 to 20 degrees cooler than when it entered. (In a ducted system, the blower is also the fan that circulates the air throughout the home.)

4 - The condenser fan circulates air across the condenser coils. As the outdoor air goes through the condenser coil, it removes heat from the coils that are very hot. This in turn removes heat from the refrigerant so it can run its cycle again, and through pressure changes, cool the evap coil.

5 - With a heat pump, the reversing valve reverses the flow of refrigerant in the condenser and evaporator coils.
In AC mode, the evaporator coils get cold, and the condenser coils get hot. But in heat mode, the evaporator gets very hot, and the condenser very cold.

Now, whichever coil is getting cold will freeze up if there is inadequate air flow across the coil, as the refrigerant in it is far below freezing, and there is not enough airflow to keep the humidity in the air from freezing on the coil.

Things that can cause poor airflow are,

1 - Dirty/clogged coils
2 - dirty/clogged filter (will only effect evaporator coil)
3 - Closed/blocked vents (will only effect evaporator coil)
4 - Malfunctioning or dirty fan

Low refrigerant will also cause a coil to freeze up, reduce efficiency and cause the system to run for long periods of time. Not to mention, shortening the life of the unit.

With a heat pump, in heat mode only, the condenser (outdoor) coil will routinely begin to freeze up in cold temperatures. This is due to the fact that the refrigerant is below freezing, and the cold outdoor ambient temp is not warm enough to keep the condensation in the air from freezing on the coil.

Note, a properly working AC should never freeze up.

A heat pump is equipped with defrost controls to prevent ice buildup.
Some are controlled by timers, some by temp.

When a HP is going into defrost mode, the condenser fan shuts down, the reversing valve reverses the flow of refrigerant and the once cold condenser coil now gets very hot, defrosting the coil. (Many people have said this process sounds like the unit is coming apart, or about to explode and are frightened by the "smoke" which is really just steam from melting ice that comes off the unit.)

During defrost mode, the secondary or "auxiliary" heat comes on to ensure that you are still getting warm air from the vents. (Again, this can be electric heat strips or a dual fuel system)

If you are experiencing cold air from the vents during defrost, that means your auxiliary heat is malfunctioning.

The auxiliary heat is used for three purposes.

1 - during defrost mode to maintain warm airflow (automatic)
2 - when the HP cannot maintain the set temp due to extreme outdoor temps. It comes on when the indoor temp drops several degrees below the set temp on the thermostat (automatic)
3 - For emergency heat source when the HP is not working. (Manual)

To recap....

Iced up coils?

Poor airflow
low refrigerant
Malfunctioning fan
failing defrost system


There are two things that can be done in a pinch to help de-ice frozen coils. This may get you by until the repairman can get there, or you can fix the system if you are a do-it-yourselfer.

HPs frozen outdoor coil in heat mode, not going into defrost?

Cover most of the vents, and turn the system onto cooling mode until the outdoor coil is thawed. then uncover vents and return to heat, or emergency heat. (this usually takes 15 min or less)

Frozen coils in AC mode with a heat pump?
Turn the system to heat with the thermostat on just high enough to get the system to come on. (again, usually takes 15 min or less to thaw.)

AC only, with frozen evap coils? (this can sometimes be seen frozen all the way outside to the compressor on the copper lines.)

Turn the system off, and the fan switch from "auto" to on".
This will usually defrost the coils within 1 to 2 hours.
(If your system has the furnace in line before the evap coil, turn the system to heat, and the furnace will defrost the coil within minutes.)



on Dec 25, 2008 | Carrier XHB123D X/Y Series Heat/Cool Air...

1 Answer

Using as heater and unit is blowing cold air


A heat pump is an air conditioner that reverses its refrigerant flow. In the cooling mode, the evaporator is cold to the room and its condenser is hot. In the heating mode, a valve reverses the refrigerant flow and makes the evaporator warm and the condenser cold.

Nov 24, 2013 | Soleus 10,000 Btu Portable Ac Air...

1 Answer

What size run capacitor do i have to get for a mitsubishi muh12tn


Best thing to do would, is look at the one that is currently inside of it, and just find a local Ac supply house, and take the capasitor with you and purchase a new one, Normaly if you look at the numbers on your current capasitor it will have the number with a UF just to the right of the number.

Nov 05, 2013 | Mitsubishi MSH12TN Air Conditioner

1 Answer

Lennox 10HPB36-10P is blowing luke warm air.


What coil is getting cold? In cooling the evaporator coil should be getting cold not the outdoor condensing coil. Verify you have the tstat setup for heat pump, verify you have a proper refrigerant charge.

Apr 19, 2017 | Heating & Cooling

1 Answer

Ok. heatpump change out, 17 year old rheem to adp air handler and weather king heatpump 3 ton outdoor. The wiring from the thermostat is killing me in the attic. I got the cooling side to work, and also...


If your heat strips come on with out the fan then you need to change the settings on the tstat for electric heat rather than gas. Or change the setting to where the tstat controls the fan. But, sounds to me like you have your tstat miswired. Did you wire in the reversing valve? Is the valve energized in heating or cooling? Tell me what colors land where at all three locations.

Jun 10, 2017 | Heating & Cooling

1 Answer

2005 s type jag a/c quit blowing cold air suddenly .just blows hot at any setting or on auto


hi,is this a heatpump or a ac unit only...if a heatpump ,there is a valve that switchs from heat tocool mode...go outside with unit running..put hand on big copper line,if it is hot your in heat mode..if cold your in cool mode....possible stuck change over valve if a heatpump...hope this helps...good luck...michael doctor airr appl.repair..843-384-8474...if need more assitance..call..its free...good luck

Mar 26, 2010 | Heating & Cooling

2 Answers

Programmable T stat


your trane heat pump energizes the reversing valve with O - orange y - is to turn on the unit make sure you have your orange wire hooked up and the tstat programming set to heatpump otherwise your reversing valve might be bad

Jun 30, 2009 | Honeywell Electronic Programmable...

1 Answer

My Lennox Air conditioner only heats


It is possible that it's the thermostat. When you turn it into cool mode, does the unit come on at all or is it silent? If nothing is coming on, then it's likely it's the tstat. Did the tech check the refrigerant charge while he was there? He should have checked it with the auxillary heat off and the unit just in heat mode. Make sure that the condenser unit outside is coming on when you are calling for cool, If you turn it on and everything comes on, go outside and put your hand on the large copper pipe coming into the unit. In cool mode, this pipe will be cold to the touch and in heat mode, the pipe will be warm to the touch. There isn't much you can do on your own with the exception of changing the tstat. If you can answer some of the questions I have posed, I can try and give you some more answers. Just remember that a check up doesn't mean its a guarantee that something won't happen the next day, it's just that everything was in working order at the time of the checkup.

Mar 21, 2009 | Heating & Cooling

Not finding what you are looking for?
Heating & Cooling Logo

Related Topics:

130 people viewed this question

Ask a Question

Usually answered in minutes!

Top Mitsubishi Heating & Cooling Experts

D. E. Hev

Level 3 Expert

1167 Answers

yadayada
yadayada

Level 3 Expert

75817 Answers

MightyMikeJr

Level 3 Expert

388 Answers

Are you a Mitsubishi Heating and Cooling Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides

Loading...