Heater is gas forced air and works fine in higher temperature daytime if in 60's, 70's. But if colder it won't turn on unless thermostat is manually moved back down then up so mercury trips again. Even had a hvac friend come out, test all of it, he replaced something but still same problem even after he checked it again but always during the day when it works fine. I put a new thermostat (non mercury switch) before he came and it didn't solve it either. It will go as hot as you want during the day and you can just put therm at 80 and it will go there. But when cold outside the only way to get it on for a few minutes each time is to rock the mercury and slowly creep up the setting, which I can't do from bed asleep. Any help appreciated:confused:

I`m confused,, you do or don`t have a non-mercury thermostat,on it right now?

There is a simple furnace/thermostat test at https://www.askmehelpdesk.com/heating-air-conditioning/heating-cooling-maintenance-repair-troubleshooting-frequently-asked-questions-58313.html

i`m confused,,,you do or don`t have a non-mercury thermostat,on it right now?

I have the original mercury Honeywell thermostat T8195B on it. I put on a non mercury one and heater still acted same way so I put original mercury therm back on.

The mercury contact works and completes circuit and turns on heater but when it's below a certain temp it won't keep cycling.

I just noticed now on a colder day that only the merc swtch for the blue lever is making the rheem criterion come on or off whether the therm is set to heat or cool. The other merc switch connected to red lever doesn't turn the rheem on or off when therm is set to heat or cool. Where can I find a manual for this thing? Thanks

Manual and install

http://customer.honeywell.com/techlit/pdf/69-0000s/69-0563.pdf

http://customer.honeywell.com/techlit/pdf/69-0000s/69-0564.pdf

there is a simple furnace/thermostat test at https://www.askmehelpdesk.com/heating-air-conditioning/heating-cooling-maintenance-repair-troubleshooting-frequently-asked-questions-58313.html


Therm for heat works fine if the outside temp is 65 or above but if it's 50 outside it just burns for a minute or less and blows for maybe 3 or 4 short cycles a minute or so a piece and then stops without the mercury moving at all. If I then just rock the mercury once it will start again and go through the same 3 or 4 short cycles for about five minutes total and stop again with the mercury still sitting in same spot... thoughts?:confused:

Jump the thermostat for the heat cycle. White (W) and Red (R) should do it. It might be easy to do this back at the furnace unless you want to take the stat apart. When it cold and it will not run jump it out and let it run. If it runs it is the tstat if it stops running like it has before it is a furnace problem.

Simple test

Jump the thermostat for the heat cycle. White (W) and Red (R) should do it. It might be easy to do this back at the furnace unless you want to take the stat apart. When it cold and it will not run jump it out and let it run. If it runs it is the tstat if it stops running like it has before it is a furnace problem.

Simple test


Thanks for the help, u mean to connect W and R correct?

Yes

yes

Aha, jumped r & w and same thing, just heats for a few minute long cycles then stops. And then disconnect r/w and reconnect it starts again with same behavior. Thoughts appreciated on what next... :confused:

The trheremostat seems to be OK.
Make sure the air filter is clean or replace it.
Does the blower fan ever come on?
If not that could trip a oevrheat safety shutting the furnace off.
Whenever you cycle the thermostat you are you are doing a reset of the control and that is why it comes back on.

The trheremostat seems to be OK.
Make sure the air filter is clean or replace it.
Does the blower fan ever come on?
If not that could trip a oevrheat safety shutting the furnace off.
Whenever you cycle the thermostat you are you are doing a reset of the control and that is why it comes back on.

Blower does come on. Filter is clean but is there a way to test it's not the filters like taking out altogether for a test or.. because it has a funny set up as you see in the pic. The heater is off the ground about a foot high and directly under it is the filter. But also there is a filter in the door of the closet as well. I've taken the door filter out. (as you see it laying on floor in picture) left door hang open, etc. to try see any change but no luck, ideas? (btw the AC has no issues if it matters) thanks, I really want to solve this:(

There is something wrong with the install of your furnace according to the pictures. Your return air is supposed to be totally isloated from the combustion air for the burner. There is a grill there in the door but I see no effective way to seal it off. Since the furnace is in a closet it is supposd to be feed combustion air from the outside. Now I will admit those pipes might be somewhere there but they do not show on the picture. See if you can take a few more pictures.

I am just wondering if this setup is causeing some or all of the problems.
Your main complaint really does not make sense to me because the furnace should run no matter what the outside temp is to start with.

BTW there is NO storage allowed in that closet also. Just thought I would mention that fact.

Now! my friend you have determined that your problem is in the furnace not in the thermostat, have you checked and cleaned the flame senser,,

heater is gas forced air and works fine in higher temperature daytime if in 60's, 70's. but if colder it won't turn on unless thermostat is manually moved back down then up so mercury trips again. even had a hvac friend come out, test all of it, he replaced something but still same problem even after he checked it again but always during the day when it works fine. i put a new thermostat (non mercury switch) before he came and it didn't solve it either. it will go as hot as u want during the day and u can just put therm at 80 and it will go there. but when cold outside the only way to get it on for a few minutes each time is to rock the mercury and slowly creep up the setting, which i can't do from bed asleep. any help appreciated:confused:
Need more info to help you. Make, Model, 90% or conventional venting, standing pilot or electronic ignition? First guess is cooler air is condensating your electronic ignition down your flue pipe. Contact me with more info, I will be glad to help if I can.

Note to kandrc: Site policy is not to ask or answer questions by PM or email.

You are asking some good questions. Many of the better people on this forum are AWOL. We could use another good man.

Check all the 120 volt wiring especially the ground circuit from the house oanel to the furnace switch. Then check to make sure the bare or green ground wire lands in the furnace. Also check all ground wires in the furnace for tightness.

Post your model and brand name so I can pull a diagram if I have one.

thnx for the help, u mean to connect W and R correct?




\\\ok,, now you have determined,the thermostat is bypassed and you still have the prob. somust be in the furnace,, have you checked and cleaned the flame senser?

Check all the 120 volt wiring especially the ground circuit from the house oanel to the furnace switch. Then check to make sure the bare or green ground wire lands in the furnace. Also check all ground wires in the furnace for tightness.

Post your model and brand name so I can pull a diagram if I have one.

Thanks for everyone's help, we'll get this...

Some more pictures. It seems as if it is some switch or sensor getting automatically tripped but it doesn't need anytime to dry or cool down or anything to restart it, just rock the mercury two seconds after it stops its four minute cycle and it goes again for the same four minutes. When it's running it all functions well so would that rule out a grounding issue?

And the reason it runs fine when indoor/outdoor temp is warmer is as I've observed the mercury is moving back and forth with rise and fall of temp. it just needs to run longer when it's colder outside/inside:confused:

Rheem criterion gas furnace

It is hard for me to see but if the thermostat has a adjustable heat anticipator try incerasing it. Usually there is a arrow that says longer with the direction to mover it.

What is the model number and brand thermostat. I will see if I can look it up.

Browse the sticky at https://www.askmehelpdesk.com/heating-air-conditioning/heating-cooling-maintenance-repair-troubleshooting-frequently-asked-questions-58313.html

Next time it won't start do the furnace/thermostat test. If it still won't start, post back with what point in the sequence it fails.

\\\ok,,,now you have determined,the thermostat is bypassed and you still have the prob.,somust be in the furnace,,,have you checked and cleaned the flame senser?


How can I check and clean the flame sensor? It's a rheem criterion gas furnace, pictures of the setup on page 2 of this thread, thanks

It is hard for me to see but if the thermostat has a adjustable heat anticipator try incerasing it. Usually there is a arrow that says longer with the direction to mover it.

What is the model number and brand thermostat. I will see if I can look it up.


Honeywell thermostat T8195B, thanks

Browse the sticky at https://www.askmehelpdesk.com/heating-air-conditioning/heating-cooling-maintenance-repair-troubleshooting-frequently-asked-questions-58313.html

Next time it won't start do the furnace/thermostat test. If it still won't start, post back with what point in the sequence it fails.


Always the same behavior, just a total of a few minutes consisting of maybe 5 or 6 burn and blow cycles then no more and that is with jumping red and white with no thermostat... :(

Ok, if you have the problem with the red and white connected, it is a furnace problem, not at thermostat problem. Go back to the sticky and note where in the start up sequence it fails.

When you move your t-stat down than back up you are resetting the control board.Its called a soft start by breaking 24v on the W circuit. If it was a major problem you would need to kill the power going to the unit to get it to reset or manually press a button inside the furnace(hard start). If you are using LP you may have moister in your tank, in cooler temps the regulator will freeze and starve the system for gas. That system should have a diagnostic light to tell you why it locked out.

When you move your t-stat down than back up you are resetting the control board.Its called a soft start by breaking 24v on the W circuit. If it was a major problem you would need to kill the power going to the unit to get it to reset or manually press a button inside the furnace(hard start). If you are using LP you may have moister in your tank, in cooler temps the regulator will freeze and starve the system for gas. That system should have a diagnostic light to tell you why it locked out.


Actually just gas line coming in so no tanks and still can't figure this thing out but thanks for any other ideas

MY POST TITLE IS INCORRECT, IT SHOULD BE - "HEATER ONLY WORK FOR FIVE MINUTES ANYTIME" temp does not make a difference

Here's more pics with a question, is the sensor in yellow circle the flame sensor? Has markings on the bottom "TOD J1" has no corrosion on it but should I try a new one and if so where in los angeles can I get one?

Other thing is the rod I thought was the flame sensor has no wires connected to it at all so what is this rod circled in red in the picture. It can slide left to right about and inch but can't come out without taking the whole assembly out, thanks guys for any help.

And other info is that by jumping red and white it will do the five minutes as noted in my other posts but it doesn't matter what the temp is outside, cold or warm it will only do that five minutes with R/W jumped. There are 4 wires you see me holding that all run to a square coil or ? But as you see not connected to anything, make a difference for the heater?

There are 4 wires u see me holding that all run to a square coil or ? But as u see not connected to anything, make a difference for the heater?[/QUOTE]


Actually a correction, those 4 wires (2 yellow, 1 WHT, 1 BLK) run to a small white plastic box, not a coil, box circled in green in photo

Yellow not actually a flame sensor. It is a rollout type overload that senses when the flame or too much heat is coming out of the furnace from the wrong place. That should not happen at that location for normal operation and it should not have to be pushed to reset unless there is a problem.

Do the two burners light off and burn normally? Blue with a bit of yellow tips?
Do you have to reset that switch in yellow?

Yellow not actually a flame sensor. it is a rollout type overload that senses when the flame or to much heat is coming out of the furnace from the wrong place. That should not happen at that location for normal operation and it should not have to be pushed to reset unless there is a problem.

Do the two burners light off and burn normally? Blue with a bit of yellow tips?
Do you have to reset that switch in yellow?


Flames burn blue real good. I noticed that they burn for 20 seconds then go off, then the fan goes on for 30 sec, then off and ignitor glows and another 20 sec off flame, then off, then fan on for 30, etc. this is the usual cycle that lasts about 5 minutes then nothing until I re jump red and white. One question is should the fan be coming on while the flame burns or is it proper for them to alternate?

Any help on where the flame sensor is on this rheem criterion II and how to clean it? Thanks

Sounds like a flame sensor problem to me unless that pilot is a 3 wire set up then it could be bad.
I have not followed this thread but have you cleaned the pilot orifice?

Sounds like a flame sensor problem to me unless that pilot is a 3 wire set up then it could be bad.
I have not followed this thread but have you cleaned the pilot orifice?


Can u look at the picture and tell me if u see a flame sensor? Thanks

I do not see a flame sensor but I do see a HSI (hot surface ignition system).

The blue line area item is a hot surface ignitor device. It should glow then the furnace should lite.

Are you on LP gas/Propane if so there could be a 5 minute lock out on your furnace?

See circuit board for a code flashing from a green LED. Open the blower door so you can see the PC board. Push the safety door switch and wait for the middle LED to start flashing a repeating code. On the blower door there is a flow chart of operation and a key to the code. THis may indicate a problem code.

Integrated control board and for some reason the ignitor is "locking out" for some reason.

Hi Darque, and everyone else, I currently have just about the same problem, actually I think it is. I've done some research and want to clean my "flame sensor" but can't find one. Heating igniter glows for 10-15 seconds then shuts down, tries 2 more times then locks down, in which I either go to thermostat and turn off and back on OR turn power switch off and back on that is located on side of furnace. Here is the part that I think should help solve our dilemma. Once I get mine going(after reseting it a gazillion times, my furnace will run properly until I turn it down to go to bed, then in the morning I go play ball with it again. I also have a Rheem/Rudd furnace and it worked fine from Oct through November(michigan). And like I said, I believe the next step is cleaning the flame sensor which I can't find. I will provide pictures tomorrow.

The sensor in this unit is called a remote flame sensor. That is all I know.

The hot surface ignitor is the flame sensor also with this style of unit.

Don't try to clean it you will only break it. If its glowing that is not your problem.

Dont try to clean it you will only break it. If its glowing that is not your problem.

Thanks t-top, it does glow fine. Could it be glowing fine but still have a problem with being too sensitive for monitoring the flame from age?

I tried posting 4 hours ago but nothing has showed so sorry if this gets duped(I'm new to forums) I have the same rollout overload sensor but mine is located above a heat shield. I did not notice a heat shield in between the rollout overload sensor and Darques burners. Could this be the reason for the trip after 20 seconds of flames? I would love to remove my heatshield and be your guinea pig but I'm not sure if its safe, and I already have a hard enough problem starting my furnace as is. I am a step up from a retard when it comes to furnaces.

The heat shield is there for a reason. Do not remove.

The heat shield is there for a reason. Do not remove.

HVAC1000 You misunderstood, I am not Darque. Just someone who also has close to the same problem as Darque. I looked at Darques pictures on Page 3. I did not notice a heat shield present in Darques supplied photos. Shouldn't there be one? Restudy Darques photos on page 3. Darques overload sensor seems to be awfully close to burners.

((HVAC1000 You misunderstood, I am not Darque. Just someone who also has close to the same problem as Darque))

Here is the problem. You should have started a new post for you only. Then you could reference his post. What happened is that the water gets muddy when over one person is posting or adding questions to the other post that is not his. Can you understand that.

Now with that being said many times a manufacturer will make running changes to the same model furnace. They will say this picture or part is good for furnace serial numbers up to 12349. Then another drawing will show a different added piece or a deleted piece and then it will say this drawing is good for units from 12350 to 32112. Same furnace different serial number. Now can you understand that?

NEVER remove any part or replace any part that is not supposed to be there.
Manufactures spend millions of dollars engineering a piece of equipment. It is UL or CSA approved the way it is shipped from the factory. What you start to remove or add things to the furnace you do two things.
First you remove the UL or CSA listing because it has been modified and you might not get paid if the equipment causes a fire. Insurance specialists look for items removed and replaced with non compliant items. Then they car refuse to pay for the damage caused to the building.
Second you could jeprodise your and your familys safety.

How do I know all this junk? Over many years as owner of a large company the State Fire Marshall would request that I visit buildings with him to give him my 2 cents worth as to the probable cause of the fire. When on those jobs I met many insurance investigators that told me exactly what they look for so there company could skate on paying some or all of the claim.

One more thing that would make it look like a bad flame sensor is a small restriction in the vent pipe it would open the pressure switch once the hot gas built up in the vent. That control board should have a light that comes on to let you know it is sensing the flame. I think it may be yellow or green. It should say flame sensor above or bellow it.

Sorry Hvac, this is my first forum. Didn't mean to come off the wrong way, just wanted to say that my furnace has a heat shield and my sensor looks just like Darque's, thought I could be of some assistance by sparking a different idea. Thought maybe by someone working on it maybe the shield didn't get replaced at some point in time.

Again I apologize for piggybacking.

No problem and yes the heat shield could have been removed but I have no way to find out for sure.

Fyi to all, had to end up replacing board & adding sensor kit. This has no sensor and rheem wouldn't tell me if the his was also a sensor, thanks for info to those who tried to help

Something in the furnace is causing a short cycle time. Could be the high limit or dirty air filter or dirty A/C coil inside the furnace plenum not allowing enough air to pass causing the high limit to trigger..