20 Most Recent Desa International RH125AT Utility Heater Questions & Answers

Is fuel getting to the nozzle? With the top off, use a flashlight to look for fuel spraying from the nozzle. When you say filter, did you mean air filter or fuel filter? The fuel filter could be your problem.

Desa... | Answered on Dec 27, 2010

The eye on these models,are apt,to go bad,clean the eye,and try it again.If this does not help,replace the eye.If this does not work,replace the board.Most likely,the eye will be the problem.It is right next to the igniter,looking at the flame.Let us know if this helps,thank you.

Desa... | Answered on Dec 25, 2010


Desa... | Answered on Dec 21, 2010


Here are a couple of tips that I wrote that tell you how to troubleshoot a Torpedo or Reddy heater...

Reddy Heater - Troubleshooting Torpedo Heaters

Torpedo Heater Pump Pressure Adjustment


Desa... | Answered on Nov 29, 2010


The problem you describe is a common problem with all these kinds of heaters. It involves the pump pressure and interaction with the air supply which changes as the filter gets restricted. The solution involves getting a new filter and setting the pump pressure. You could also have water in the fuel but all this is explained in my tip at http://www.fixya.com/support/r4124129-yearly_maintenance_reddy_heaters which also tells you where to get the parts.

Thanks for using FixYa and for the great rating and testimonial. Great ratings keep experts helping to solve problems. Thank you.


Desa... | Answered on Nov 20, 2010

sounds like your pressure is too low. on the back of your heater is a yellow plug with a slot for a screwdriver. turn it about a full turn and see if it will run. the other yelow plug is where you can put in a pressure gauge and see the pressure of your pump. you should put a gage in the hole and then turn the other plug unitil you increase the presure and a 1/2lb.

Desa... | Answered on Mar 15, 2010

replace the pc board,I dont know why the desighn something with a pc board that is around a lot of heat and contaninates ,not unless they want to just sell parts, I hope this helps

Desa... | Answered on Dec 14, 2009

It sounds like a plugged fuel line, possibly fuel filter, or a bad pump.
Good Luck,

Desa... | Answered on Dec 03, 2009

if its as ancient as you say it probably has an ignition transformer,open up the unit and isolate the transformer and check primary/secondary transformer windings for continuity,if so then either the electrodes or spark plug thats on the secondary transformer could be defective,be careful POWER OFF secondary can have up to 4,000v.a.c. when plugged in

Desa... | Answered on Aug 27, 2009

At this point I can't tell you the problem. YOU must troubleshoot and find out whether the lack of ignition is a fuel delivery problem or an electronics problem. Click on the link. Might be a good starting point. Troubleshooting tips.

Desa... | Answered on Apr 22, 2009

  1. Does the ignitor glow for 5 seconds when the unit is started?
  2. What is the air pump pressure reading?
These are the starting points for troubleshooting a heater that has an ingntor.

Answer these questions and maybe someone can get you started.

Desa... | Answered on Mar 13, 2009

Sounds like a bad thermostat! (A common problem with this model) replace and it should work again!

Desa... | Answered on Jan 30, 2009

It's hard to tell from your description but if 110v is passing through the thermostat (is it???) and 110v is making it to the ignition control board and nothing comes out, then the board and/or photocell needs to be replaced.

parts reference list

Desa... | Answered on Dec 26, 2008

John- the ignitor does not stay on for the duration of the running time. It only stays on for the first 5 seconds. This is long enough for the flame to ignite and perpetuate itself, assuming the fuel delivery system is up-to-par. The photocell monitors the flame color and if the flame becomes off-color then the photocell tells the control board to shut the unit down. Naturally, too rich or too lean affects flame color.

Now, I'm confused by your description "the heater cycles 3 times". Tell me more.

I'm glad to see that you checked the pump pressure. Have you used soapy water to check for air leaks all the way to the nozzle? A leak in the airline, fuel line, or a crack in the nozzle adapter will cause no fuel delivery, or reduced fuel delivery as well as reduced atomization of the fuel - all of which can cause a lack of combustion. A restricted fuel filter will cause starvation.

Eliminate all possibilities of a fuel delivery problem before you start blaming electronics because there is not much way to test the board or the photocell successfully without DESA's diagnostic tool. Unfortunately, replacement of the componants is cheaper than the tool.

Desa... | Answered on Dec 23, 2008


Feb 7, 2018 - If it does not work for you, you will need to replace the gas valve. It's expensive but I'm about positive that cleaning it will fix it. ... Hi it is blue with a slight yellow tip ... at www.desatech.com , then go to "Wall Heaters" then click your model ... I fixed this by dismantling the fire and right next to the control knob ... Gas wall heaters vangaurd model VP2600C
10 answers
Jan 31, 2014
SOLVED: I have a vanguard propane wall heater, 5 ...
2 answers
Jan 6, 2010
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Desa... | Answered on Feb 28, 2019

If it's a direct spark ignition type heater maybe that's how it's designed to.work .When called for heat pilot open allowing gas then ignitor spark and ignite the pilot then gas valve open and allow gas through burner then unit fires off .
Once temp is met pilot valve closes and pilot out .

Desa... | Answered on Feb 19, 2018

pilot injector . burner injector , change reg . you have to change all the above .

Desa... | Answered on Feb 13, 2018

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