Heater wont turn on

Check your fluid level in the radiator and the flow to your heater core

If this is a MiniMax NT STD heater, the part on the right on the bottom is not the ignitor, it is the flame sensor. The part on the left with 2 wires is the ignitor. The E04 code is for a fan failure. This means that either the fan is seized, or the air switch is bad, or the air switch tubing is cracked (this is most common)

If you hear the fan is going, then turn off heater and check the air tube connected to the air switch (3" round disk on right side under the square steel enclosure with 2 wires coming off it on the front).
Remove the tube and inspect it to make sure there are no cracks.

If the tubing is good, and the fan works, you need a new air switch.
If you know how to use a multimeter and/or just need more help, you can reach me @ [email protected]

Does the blower motor start when you plug it in/turn it on? It may take around 5 seconds if your heater has a HSI(hot surface igniter). If it does you need to check the igniter and the fuel flow. Either way, remove the top of the heater. You will be able to see the fan, igniter, and fuel nozzle. Turn the fan by hand to see if it turns freely. If it does, watch out for the fan and turn the heater on. Look for the igniter to start sparking (spark plug type) or glowing (HSI type). Next, use a flashlight to look for fuel spraying from the nozzle. If fuel isn't spraying, try cleaning the fuel nozzle and check the fuel filter. Watch out for the HSI, if you have one, they are very brittle and easily broken. If you still don't have fuel flow after cleaning the nozzle and the fuel filter, you may have an air pressure problem. Let me know and I will tell you how to check it. Don't forget to rate the answer if it works.

the fan may need replacing it may be faulty, but on the ither hand how long since furnace serviced it may be over temping before fan kicks in which means needs the air flow looking at! air flow on a majority of heaters is important if you don't have enough the heater will high temp and shut down, but it sounds if it may be the fan itself if the heaters turning off before fan starts it could be because of a faulty sensor or fan motor ceased and not spinning causing it to trip so firstly look at fan and see if you can see why its faulting if it is also i would check your airflow makes sure that clean enough to get good air flow and if ducted heating check the return air to unit and if has filter take out and try running there could be a lot of reasons for this but usually its air flow or fan if you are not electrically minded i would seek a qualified repair agent for furnace

Problem with the thermocoupler its not producing a minivolt of 250 plus that is needed to open the main gas valve

http://www.laarsman.co.uk

Miles

no fan comes on when engine cold start up .but it will come on when you turn on air conditioning or defrost on .if engine idling a while when temp get 190 degree the fan will kick on.if over heating you got air in system .wait until cools check coolant add more .crank engine let it idle few. minutes when start warming up turn off engine wait a while before removing radiator cap so you wont get scald.add more coolant .crank it again starting warming up turn off engine wait a while .add coolant .keep doing this procedure until your coolant stop dropping off .if you do this more than 6 times you got a leak some where.check crank level for signs.if oil level higher than normal.if everything looking good.when engine cool make sure add coolant to over flow jug cold level mark.

The problem is most likely the over heating sensor thermostat located directly under the heating elements - The reason the over-heat safety thermostat sensor is tripping the warning buzzer is because either the cool air fan intake is obstructed with dust / dirt, or the fan motor stopped rotating, or the over-heating condition thermostat is defective, or over sensitive - Usually when the cool air intake is obstructed for any reason, the heating elements will glow brighter, and hotter without good air flow, and the elements may start to bow downwards closer to the over-heating safety thermostat - However, if the safety thermostat is defective, it can trigger the warning buzzer even though there may not be an over-heating condition / event present - The buzzer warning going off prematurely also occurred with my Holmes space heater - I checked the air flow first, and then the appliance tip-over switch second - Both were found functioning properly - It wasn't until I replaced the safety over-heating thermostat, did the buzzer stop going off moments after I plugged the space heater in an outlet.

most fan forced wall heaters do not move a lot of air. check the cfm rating on the heater. the fan sucks in air from the bottom and forces it up to the top where the element is. broan and nutone have good air flow.