20 Most Recent Desa International CBN30T Central Heating System Heater Questions & Answers

Did you bleed the air from the pump .

Desa... | Answered on Apr 12, 2017

I need full diagram cables converter flor a sequoia coleman [email protected]

Desa... | Answered on Aug 15, 2016

balance the rads.
upstair radiators turn all valves off,heat will then divert downstairs,open valves upstairs 4 turns on locksheilds and number 4 on trvs if u have any.
then if that does not work get a combi or powerflush.
if u cant afford then drain a little from rads,get x300 sludge remover from plumb shop and put in header tank(not hot water tank).
then fill system up and repeat balancing.


Desa... | Answered on Nov 17, 2014

Look it is not when thawing that they burst, if they were going to burst they would have done that already. The pipes burst when they freeze and the water expands, it just so happens you do not find that until you defrost the pipes and the water can flow. You really need to visually inspect all of your piping while it is defrosting and then isolate the leak for repair. If they were going to break they already did. Good luck and I am praying for you!!

Desa... | Answered on Oct 30, 2014

yes change the thermocouiple

Desa... | Answered on Nov 02, 2013

I worked on plenty of them. Usally it is the termocoupling needs replace. It's easy to replace and you can pick that up at Fagers, Michells, or a heating and plumbing store.

Desa... | Answered on Nov 02, 2013

Your auto fill is stuck open, is there any way to shut off the supply of water to the boiler?

Desa... | Answered on Apr 25, 2013

Rad needs taking off and flushing out , if more than 1 rad cold you may need a system flush

Desa... | Answered on Jan 15, 2013

HI right first i would look at a worcester greenstar combl
best you can get and you have full back up from worcester leave all rads with stats as they are i think you will have to remove one , the that would be the bath room also the greenstar comes with a clock bulit in these are on the worcester bosch web site i have been a gas fitter fot 30 years and this what i would go with a really good combi, you can also get awire less room thermostat for this hope this helps

Desa... | Answered on Aug 04, 2012

Send me your email and I will send you a pdf of user instructions

[email protected]

Desa... | Answered on Oct 24, 2011

The model # you listed is for a vent-free, natural gas, space heater and requires no electricity to operate. Unless, you have the optional blower. If the blower accessory is what's blowing the fuses, there is a short in wiring to the blower motor. Other than that, there is nothing else about this heater, that would be blowing fuses.

Is the above, the problem you're having? If so, unplug the blower from the wall outlet, until it can be repaired or replaced. The heater will continue to operate and heat with out the blower.

For more information about your heater, go to the link below.


Desa... | Answered on Mar 04, 2011

This is simple to light. Turn the selector switch to pilot and push it down then push the striker button and watch it light. Hold for 30 seconds and then let off. Turn the selector switch to the desired comfort level and it will work.

Desa... | Answered on Jan 27, 2011

One possibility is that theThermo Couple is beginning to fail'
What is a Thermo Couple? (TC)
The Thermo Couple (TC) is a small Rod-shaped device with a couplewires coming out the bottom.
The TC actually generates a small electrical current from the heat ofthe Pilot.
This electrical current is sensed by the controlboard, or the Main Gas Valve.
As long as there is a pilot, it is safefor the Main gas valve to open, and admit the large amount of gas into theheating burner.

Now-- What helps this TC work the best?
It needs to be just at the edge of the pilot flame--- Not too muchin the flame, or the resulting poor combustion of the pilot flame, results insoot forming on the TC-- which insulated the TC from sufficient heat.
Obviously the TC has to be clean (of soot) in order to receive enoughheat, to generate the needed voltage to tell the valve that it is safe to open.
And age does deteriorate the TC-- some last a few years, but thatis about the end of life for most.
Replacing requires getting down where the TC is, and with a screwdriver (usually)-- loosening the bracket that holds the TC. Payattention to where the wires are routed, and any polarity indicated on the oldwires, and duplicate on the new one. Duplicate routing, and polarity, andposition the new TC at the edge of the pilot flame.
Pilot flame is maintained by pushing some over ride button-- for aminute or two, until when you begin to release the button, you can feel thatthe voltage generated by the TC is now holding the pilot valve open, instead ofyour pressure on the 'start' button.

Any further Questions, let us know..

Mack B

Desa... | Answered on Jan 20, 2011

Hi, 24 volt thermostat sends a signal to the control module. The control module will indicate a call for heat with a light on the control either blinking or remain solid depending upon model. The inducer (exhaust) blower will purge all gasses from the furnace and pressurize a pressure switch. Once the pressure switch tells the module to continue, the electronic ignition will energize and send 120 volts to the igniter. The igniter will glow and you will be able to see it if viewed thru the small inspection port. Once the igniter gets hot enough, it sends a signal to the module opening up the gas valve (24 volts). Either a pilot will come on or the burner tube will ignite then spread the flame to all burners. Lastly a safety sensor will be looking for a certain temperature within a few seconds and the furnace will continue to operate and the room air blower will turn on in a minute or two.

What could go wrong? The unit will not run if there is no signal from the thermostat (bad thermostat or broken wire), the control module does not sense a signal from the thermostat (bad control), the inducer does not energize (bad motor), the pressure switch does not close (blocked vent piping, bad switch, plugged condensate hose), the igniter does not energize (bad control, bad igniter), the gas valve does not open or there is no gas (bad gas valve, broken wire, no gas), the pilot does not light (dirty pilot), the burner does not light (bad burner, plugged orifice, not enough combustion air), the flame does not spread to each burner (bad flame spreader, dirty flame spreader, more bad burners), the flame safety sensor does not detect flame (dirty or bad flame spreader, bad flame sensor, broken wire, bad control), or the room air blower does not energize (bad fan motor, bad control).

You likely have a dirty pilot.....

Desa... | Answered on Dec 04, 2010

okay could be a slight blockage in the pipe did he do a hot and cold flush on the system ? pump speed could be too high or low or they could be air lock in the system ,

Desa... | Answered on Sep 04, 2010

you could re locate your therocouple away from flame

Desa... | Answered on Apr 10, 2010

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