How to eliminate thermostats from space heaters

If it's an exact replacement and the cut-out temp is lower than the old one...maybe there is an adjustment.

Hi, Let me guess, the heater element got shorted some how and over heats triggering safety shut off switch. Are you trying to get rid of built-in safety shut off switch and get fire started? Trouble-shoot for real cause of the problem begining with careful visual inspection.

No, the answer is to REPLACE the "thermostat" - which is really an overtemperature protection device. If the fan is working properly the overtemp protector has gotton weak.

I would definitely NOT remove or bypass the protection.

I understood he replaced the entire heater with "an exact replacement" which has failed in the same way as the original (which is understandable if it is a marginal design)

The words "exact replacement" refer to the visual inspection of the heater.... same color, same shape, same diameter... etc. Not toan exact part number or specification conrrespondance. I don't remember but I would think that the first failed for the same reason an incandescent light bulb fails: at some point along its length the element rusts and/or burns through. The element is mounted on porcelain stand-offs.

I don't know why you have to over-complicate this whole affair. I'm not really interested in why the old one failed. The new one doesn't fail at all. It acts like it probably should, turning itself off when it thinks you've had enough heat -- naughty boy! You're only entitled to a mild warming. Think of the children!

I've had similar spot heaters for the last 40 years but only recently have I noticed that they all seem to be "thermostatically controlled"

-- even the gas ones.

The "safety shut-off" switches on these type of heaters are usually the type that turns the electricity off when the heater is knocked over. It doesn't apply to heater mounted on the ceilings or screwed to the walls.

Wrong! What a load of crap! The thermostat regulates the temperature indeed but it's not a safety device. It supposedly imitates the temperature control on the central heating. Have a look at some of the cheap-o ones in the discount stores and read the boxes.

I never understand why you lot just don't reply to the questions asked. No editorializing!

Because the answer to the question is it is NOT thermostatically controlled - it is thermally protected. Thermostatically controlled heaters have an external adjustment knob, and the heater cycles to maintain temperature. Most of the ceiling mounted "radiant" heaters are NOT thermostatically controlled.. The wall mounted timer is the give-away.

The behaviour of the heater has changed over time. The thermal protection devices have a habit of failing that way.

The heater in question is similar to the Nutone QT9093. ()google it) or the Qmark QCH1151.or a Broan Model 157 .

Note both of them specify they have self resetting high limit switched.

I've fixed quite a few of them over the years - the thermodiscs don't last forever.

Sure we do, but you won't get any help with that from anyone who is rational.

You have been given some info about REPLACING the thermodisc protection device. Probably has the cutout temperature written on the side. While that's certainly a failure mode, I'd first look at increasing the airflow to keep the temperature lower. Clean out all the dead mice and see if it works better.

If you insist on defeating the fire protection, save some additional $$$. Sell the family burial plot and go for cremation. Insist on 50% off because you'll already be half done.

It's not clear to me if it's an actual safety protection device that only triggers if some unusual high temp is reached because something went wrong or if it's as the OP thinks, a normal temperature regulating type of thermostat. IDK about this specific type of heater, but for heaters in general, it's not unusual for them to have one of each, with the "safety" one being a thermal fuse that opens once and for all.

In any case, it would seem there are two choices:

Ok, I re-read your post and realize that it does appear to be a problem with the thermal protection breaker and you should not bypass it.

The industrial equipment I worked on for my job, used them and though it did not happen often they could fail in just the way you describe.

To replace one is absolutely no more time consuming or difficult than bypassing it and they certainly don't cost much.

What you can do until you fix it is simply not turn the heater on until you step out of the shower...or better still get your other bathroom fixed.

Hi, How can you knock off a heater mounted on the ceiling? That shut off switch is really a thermo sensor. They are every where. If it is bi-metal type, mostly it is adjustable. Knock over sensor is usually a mercury switch. I am just saying. Safety first is being naughty?

Hmm, OP is a stuborn man.

And obviously not too bright either.

On Friday, January 23, 2015 at 8:08:07 PM UTC-8, snipped-for-privacy@nowhere.gov wro te:

You need to determine if the power is being sent when it cuts out or the po wer is no longer being sent to the heater, a celling heater is not optimal as heat rises I guess you know this, the unit sounds like the high limit safety is tripping, may be due to age or dust but bypassing is not a good idea, replacement will be the way to go if cleaning it wont work.

The wall-mounted timer has nothing to do with the heater. It's just a standard rotary timer that could be used for anything.

The Broan 157 is exactly the model.

I have had electrical space heaters on and off for at least 40 years. You plug them in or direct wire them. When the electricity is on -- either switch or plug -- the elements glow and the room warms until you decide to turn it off. Simple eh? I've never had one cause a problem. Only the most obtuse, those afraid of their own shadow, the "think of the children" crowd, require something else and of course that was my original thought. Ah! It appears that I was right.

So now I have to strip all this unwanted "protection" out of this heater.

You know back is the good old days people would help others to defeat "the man". How do you defeat copyright protection for some piece of software or what equiptment do you need to eliminate Macrovison? (A Time Base Corrector is the answer to the latter.) Today it seems you're as likely to encounter some "goody two shoes" as a fellow fighter against the system.

Oh well, looks like I just have to do it on my own.

No, you were wrong. The protection is required for UL approval, removing the protection voids the UL approval and also voids your fire insurance. Only a total imbecile would remove or bypass the protection.

No. REPLACE the protection.

Only someone with significantly less sense than a total imbecile would advise you on how to defeat the protection.

No s*it!

One helper makes a copy of a music song, your kind of helper is likely to burn down the house. Who sung that "burn down the house" ah, never mind.