Question about Mr. Heater MH12CS with Electronic Spark Ignition Heater

2 Answers

Heater wont stay lite

I flip the switch and it lights and works for 10-20 seconds and the flame goes out the fan stays on

Posted by on

  • tod2 May 11, 2010

    this unit is older than the mh12cs unit. not sure of the model#



2 Answers

  • Level 1:

    An expert who has achieved level 1.

    Problem Solver:

    An expert who has answered 5 questions.

  • Contributor
  • 8 Answers

Needs a service, make sure there is no dust between the thermocouple and the pilot assembly. An air compressor should do it.

Posted on Dec 04, 2013

  • Level 3:

    An expert who has achieved level 3 by getting 1000 points


    An expert that got 20 achievements.


    An expert that got 10 achievements.


    An expert that got 5 achievements.

  • Master
  • 1,420 Answers

Can you give us a brand name and model number?

Posted on Jan 18, 2008


1 Suggested Answer

  • 2 Answers

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

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.
Good luck!

Posted on Jan 02, 2017

Add Your Answer

Uploading: 0%


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



Related Questions:

1 Answer

Totai heater wont stay on after lit

Without a pilot flame sensor signal the pilot light will not stay on and the heater won't work. Try Replacing the pilot flame sensor, the pilot flame burns on to it and it connects to the valve. It looks like a wire.

Nov 26, 2017 | Rinnai RHFE-1004FA 38,400 BTU Energy Saver...

1 Answer

Goodman furnace gmh95090cxac wont stay lit keeps clicking will lite then clicks back off what would be the problem

Hello, if the burners light but do not stay on for more than 10 seconds, I would clean the flame sensor. The flame sensor is a metal rod that is on the opposite side of the Igniter, sometimes it gets coated by oxidation and does not sense the burner flame and shuts the Furnace down. To clean to kill power to tje furnace, remove flame sensor and clean with a steel wool, then reinstall and start Furnce back up. If this does not work then most likely the Igniter is too weak to ignite the gas and will have ro be replaced.

Oct 29, 2012 | Heating & Cooling

2 Answers

I have a 11 year-old york diamond 80 furnace. The flame sensor lights up and ignite the flame for about 5-6 seconds. Soon the flame goes out once again. There's this clicking sound that is heard every

You need to clean the sensor with steel wool so its very clean check sensor connections . If it is still not working you could change sensor also check out the pressure switch .

Jun 20, 2017 | Heating & Cooling

1 Answer

I light the piuolot button and when i let go of the pilot button the pilot goes out does not light burner wont stay lit

When you light the pilot lite you have to hold the button down until it gets the element hot enough to stay lit. If you hold down the button and lite the pilot and let it go right away it will go out. What to do is hold down the button and lite the pilot and continue to hold the buttn down for about 45 seconds to a minute then let it up very slowly and you will see if it is going to go out by the flame getting smaller as you let up on the button. If it does start to get smaller conitnue to hold it again for a few seconds and repeat the process of letting it up slowly. when the control element gets to the right temperature it will stay lit then turn your valve to "ON" and the fire will start up and continue to heat the water.


1 Answer

My heater isn't blowing any heat. I hear the fan come in, and i think i hear the gas come on, but nothing comes out of the vents. The fan only comes on for a couple of minutes and then goes off.

Ok so here is a sequence of the heater lighting and the solution for your problem...
1. Thermostat calls for heat. 2. Draft inducer motor starts. 3. Pressure switch attached by a small plastic or rubber tube senses the negative pressure produced by the draft inducer and closes. 4. Draft inducer runs for 30 seconds to a minute before you hear a gas hissing sound. The ignitor did not glow, the flame sensor (a small metal probe about 1/8" in diameter, with a white porcelain base) does not sense the flame, so after 8 to 10 seconds the hissing sounds stops with no ignition of gas to heat your home. Your furnace shuts down and goes into a lock out condition until you turn your power switch back off and on again. Then the sequence starts all over again with no ignition of the gas. Solution:You probably need to purchase and install a new ignitor. I would suggest that you inspect your ignitor closely for cracks.Make sure you do not touch the ignitor with your bare hands. If you do not visually see a crack, then you could have a furnace control board problem or a limit, rollout switch problem. Please see "limits, rollout switches & furnace control boards" further down on this page. The furnace's control board might not be supplying the voltage to the ignitor. If your furnace lights and the gas stays on for 8 to 10 seconds, then shuts right back off, then you need to clean your flame sensor with light sand paper or steel wool. You might need a new flame sensor, but most of the time they can be cleaned an will work well after cleaning. Please see the pictures below to help you identify a flame sensor.
Thanks and I hope this helps. Feedback apprec.

Jan 28, 2011 | Honeywell Electronic Programmable...

1 Answer

Hello, The problem is the ignitor comes on for a few seconds then goes out. The fan keeps running but no heat is coming out. Any suggestions? The model we have is Amana air command 90. Thanks.

If your furnace lights and the gas stays on for 8 to 10 seconds, then shuts right back off, then you need to clean your flame sensor with light sand paper or steel wool. You might need a new flame sensor, but most of the time they can be cleaned an will work well after cleaning.

Nov 28, 2010 | Heating & Cooling

1 Answer

Not staying lit

Remove the front panel and tape down the door safety switch so the unit can turn on when door is off. Turn up thermostat to make sure there is a call for heat. The circuit board should indicate a call for heat with either a blinking light or a solid light. Then the exhaust fan should turn on clearing the venting from any fumes. When the fan has ran for a few seconds, the igniter should start glowing orange. After it reaches a predetermined temperature, the gas valve should open with a click. The flame will start at the burner closest to the igniter and travel away from the igniter. There is a small flame rod located in the flame path on the last burner that tells the circuit board it feels the flame. If the flame goes off within a few seconds of starting, you have a dirty flame rod. Clean it with a scotch-brite pad. Once you get the flame to stay on for 90 seconds or so, the room air blower will turn on. If it tries 2 or 3 times to start but does not, the circuit board will record a code and display it with a blinking light. Look on the door panel for a wiring diagram. There will also be a Diagnostic chart that will tell you what the pattern of blinking lights represent.

Good Luck!

Nov 23, 2010 | Goodman GMS80453ANA Open Flame Mid-Size...

1 Answer

Furnace will start and sequence fine run for five minutes or so then the flame cuts out....miller type furnace put a new board in last year so now it cycles three times and goes into soft lockout.....

Clean the flame sensor.

If your furnace lights and the gas stays on for 8 to 10 seconds, then shuts right back off, then you need to clean your flame sensor with light sand paper or steel wool. You might need a new flame sensor, but most of the time they can be cleaned an will work well after cleaning.

Nov 19, 2010 | Heating & Cooling

1 Answer

Pilot turns on but when I switch to turn it on,

When you light the pilot, are you holding it down for 30-60 seconds. When you release the pilot button, does the pilot flame stay lit? Or does it only go out when you turn the knob to on position. Make sure the pilot flame is heating the end of the thermocouple and that it's a strong blue flame, not a lazy yellow pilot flame. Make sure the tip of the thermocouple is not burn't off, which usually happens with lazy yellow pilot flames. Replace thermocouple is nothing else works.

May 13, 2010 | Coleman 5040-751 BackHome Open Flame Patio...

Not finding what you are looking for?
Mr. Heater MH12CS with Electronic Spark Ignition Heater Logo

196 people viewed this question

Ask a Question

Usually answered in minutes!

Top Mr. Heater Heating & Cooling Experts

Paul Carew

Level 3 Expert

3182 Answers

Dan Webster
Dan Webster

Level 3 Expert

8220 Answers

Mack Baxter

Level 3 Expert

383 Answers

Are you a Mr. Heater Heating and Cooling Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides