Tecma Toilet issue - 2007 Signature

[grizzly]

Have my Tecma toilet with 2 buttons and the red light comes on when full. Tank was emptied and flushed but red light still on and I can't flush it. Any solutions or work arounds?

[Dr4Film]

Bad sensor somewhere. Most likely on the tank. Possibly jumper the sensor once you find the faulty one.

Edited Wednesday at 10:08 PM by Dr4Film

[Rikadoo]

OMG🤦‍♂️ im always telling people electronics will fail at the most inopertune time but takes it to a new level🙀💩😳 dont mean to be laughing at a issue like that , but i had no idea you could be locked out from a toilet, so like is there an overide with that system???

[Dr4Film]

Obviously, the Tecma Toilet was engineered by someone who doesn't own an RV and probably has never even been inside of one.

[Frank McElroy]

35 minutes ago, Rikadoo said:

OMG🤦‍♂️ im always telling people electronics will fail at the most inopertune time but takes it to a new level🙀💩😳 dont mean to be laughing at a issue like that , but i had no idea you could be locked out from a toilet, so like is there an overide with that system???

Look at the side of your black tank and remove the wire on the high sensor.  But, be absolutely sure the black tank isn't full.  If it is full you could pump black water out your roof vent...

[grizzly]

16 minutes ago, Frank McElroy said:

Look at the side of your black tank and remove the wire on the high sensor.  But, be absolutely sure the black tank isn't full.  If it is full you could pump black water out your roof vent...

There are 2 sensors on top black tank and each has 2 wires, one brown and one black. Have disconnected all of them and red light still on

[Frank McElroy]

I was afraid that might happen.  The electronics have a fail safe that if a sensor isn't reading if defaults to a full tank.  Is it easy to peel the sensor off the tank wall?  

Have you already tried flushing the tank?

[grizzly]

Do those sensors just mount to the outside of the tank or do they go into it internally?

1 minute ago, Frank McElroy said:

I was afraid that might happen.  The electronics have a fail safe that if a sensor isn't reading if defaults to a full tank.  Is it easy to peel the sensor off the tank wall?  

Have you already tried flushing the tank?

Yes I have several times. I saw how to by pass it to get it to flush. I guess the next thing is to take the señor off then tank

[Frank McElroy]

OK, have you tried this - press and hold the flush more than ten seconds.  This should bypass and override the red light.

To bypass the sensor insert a 620 ohm resistor instead of the sensor.

[Frank McElroy]

1 hour ago, grizzly said:

Do those sensors just mount to the outside of the tank or do they go into it internally?

Yes I have several times. I saw how to by pass it to get it to flush. I guess the next thing is to take the señor off then tank

Yes, they just paste to the side of the tank 

[MyronTruex]

Quote

I have to press both buttons at the same time for about ten seconds to get the emergency flush. On my 2008 Endeavor the tank flush was at the opposite end of the tank providing little cleaning of the sensor end of the tank. I installed a second flusher above the sensor area and that really helped but since we fulltime I was always concerned about build up. Using a deck hole access device (???), I have a clear cover and can see if the tank is full. And when needed, the cover unscrews and my pressure washer can easily clean the tank spotless. 

At one point I moved my full tank sensor up a bit because it was reporting full when at the half way mark which was annoying. 

 

[grizzly]

Well the lights went back to green over night without doing anything. Strange but happy. I did do the by pass flush to use it. 1 went green about 8 hours before the other one did. Must be toilet gremlins in there. LOL Thanks to everyone especially Frank.

I found this and it might be helpfull to others:

https://www.thetford.com/wp-content/uploads/2015/01/38996A-TecmaSilenceRV-Eng.pdf

[MPfeif]

I have had this issue, and the solution has been to 1) wait overnight like you did and/or 2) flush the black tank using tank blaster 3) driving with the black tank half full 4) always run water in the the black tank flush while emptying and/or 5) use a good enzymatic black tank treatment.

Because of the where the sensors are located at the very end of the tank, and both toilets (if you have two) dump into the tank at about the same spot, I suspect that a buildup there is causing the issue. While the capacitive sensors the tecma's use are less sensitive to crud building up than the resistive tank level sensors, they're not immune.

The toilets actually use separate sensors for 1/2 full and full, so if you look at the end of the tank (by the aquahot, behind the plastic panel, you'll see four black rectangular sensors stuck to the end of the tank.

[Dr4Film]

I wonder if the tank sensors that are used for the SeeLevel Tank Level Systems would work for those Tecma toilets. Those sensors are significantly more reliable than the ones used by Tecma.

[Tom Cherry]

Reading this topic out of curiosity and also to understand.

Frank has posted a solution.  If I understand the circuit as well as also having helped some folks over the years, this is a “unique” circuit.

See!evel is a capacitance system….

External tank monitors use a completely different method. SeeLevel is a dielectric (Capacitive) system that senses the difference between Air and Liquid

The Tecma sensor is a “POINT” contact or an inductive sensor.  If you read the literature, there are TWO and each has a specific value….and are marked HIGH and MEDIUM.  Frank provided the specific “bypass or work around” solution…..with the caveat that if the tank iS FULL….then there will be consequences.

Thus….SeeLevel will not work.

BUT….having been a process engineer and doing a lot of tank and level control projects….I read the SeeLevel manual.

The issue can be….Faulty HIGH sensor or too much “crap” where the sensor is mounted so that it THINKS, the level of the tank is high.

I’d suggest reading the SeeLevel manual on cleaning and then be prepared, as they state, to do periodic maintenance and try to keep the interior wall as clean as possible.  My take is that when the tank is not used…..the moisture that has wicked up the side walls will evaporate or dryout…..thus, the sensor gets a reading commensurate with a “clean” tank. Those of us with the pass through or contact probes know that after driving and getting on site, our black tank reading is useless….but in a day or so, it is a little more accurate.  Many folks stress and try to make that system accurate.  It will NEVER be such.

The SeeLevel has a calibration or adjustment….the Tecma is not designed to be “field calibrated”.

It MIGHT be possible, if the sensor is OK, to remove and reposition (horizontally) to another location on the tank sidewall that is not subject to build up….or not as bad….the SeeLevel info on the internal dynamics and how to keep their system functional is some of the best and most researched out there.  Way too many myths of how to have a pristine and spotless tank interior…..all you can can do is MINIMIZE the buildup….
 

 

[Dr4Film]

@Tom Cherry Can you explain the difference between "inductive" and "capacitive" to me as I have limited knowledge in that area of expertise, please?

[cbr046]

3 hours ago, Dr4Film said:

@Tom Cherry Can you explain the difference between "inductive" and "capacitive" to me as I have limited knowledge in that area of expertise, please?

I'll take a shot at it . . . .

Passive components have 3 major properties - resistance, capacitance and inductance. 

Resistance is simply the component's "resistance" to current flowing through it.  Voltage and Current will flow at the same time, even in an AC circuit.

Capacitance is when a component builds a charge on one side vs the other, and only occurs in AC circuits (or pulsed DC).  Current will flow quickly while voltage across the device lags then builds up.  Think of 2 large metal plates very close to each other.  The plates aren't physically connected so they have infinite resistance.  As voltage is introduced current will flow through to the other plate until the charge is saturated across the plates.  Removing the voltage source will still have voltage across the plates until the surrounding circuit bleeds off the voltage. 

Inductance is when a component resists current initially then allows it to flow after a short period.  In this case current resists flow when voltage is first applied, then as the magnetic properties of the device are saturated current flows up to the resistance of the wire.  This also called current lagging voltage.  As frequency of the AC is increased so is the inductive (magnetic) resistance.  We're stuck with 60 Hz AC for air conditioners and refrigerators but hi-efficiency power supplies, like in TV's, computers, chargers and other electronic devices will run in the tens of thousands of Hz (I seem to recall 40 kHz being typical).  In these circuits the inductors (transformers) and capacitors can be much smaller. 

MOTORS are great examples of inductance because the windings are thousands of turns of wire within a, when voltage is applied, magnetic field.  But now voltage is leading current and that isn't efficient so we introduce capacitors to counteract the motor's inductance.  Think of it as ying & yang - you need both to balance the other out otherwise you'll have current and voltage through the device at different times, expressed as "degrees of phase".  Zero degrees will move the motor at it's maximum efficiency.  At some point if current and voltage are out of phase enough the current will burn up the windings in the motor. 

Another example are ignition points in an old gas motor.  The ignition coil (transformer) has enough inductance that when the points open (creating hi voltage for the spark plug) the current would continue to flow causing arcing and pitting the points.  So a capacitor (condensor) is placed across the points to supply current to the coil for a very brief period of time while the points gap gets large enough that they won't arc. 

Does this make any sense?

- bob

 

 

[Patricia Ferrara]

Hi all!

With our Tecma toilet, we’ve found that flushing the black tank for at least 15-20 minutes after each dump, helps to keep the Tecma sensors functioning. We’ve also switched to using Unique brand black tank additives:(https://uniquecampingmarine.com/?utm_source=Unique+Camping+%2B+Marine+Newsletter&utm_campaign=47b2052451-EMAIL_CAMPAIGN_2024_09_19_02_50_COPY_01&utm_medium=email&utm_term=0_-bfd3fdcfdb-[LIST_EMAIL_ID]&goal=0_d09517132e-47b2052451-471153561&mc_cid=47b2052451&mc_eid=18912c88ea

They have both the normal additive, & a couple other formulas that you add the entire bottle that helps to clean the tanks (we try to use THAT every 3-4 months). Their products have helped keep the Tecma system functioning; however, our sensor readings at the control panel & in the wet bay have not been restored (we think that those sensors are “toast” & aren’t too concerned about them).

Just pray that your masticating motor never dies! I had to replace ours, and although it wasn’t too difficult, it was a PITA!🤣

[Tom Cherry]

Catching up.  Great comments and such.  Bottom line.

The sensors on a typical Monaco control panel or such are 12 VDC circuits.  There are 4 sensors.  One at Bottom is “NEG” or ground.  The 1/3; 2/3 & full are the POS.  Now it may be reversed…. Bottom line.  When the liquid is BEOLW 1/3…..there is NO LIGHT.  But when the liquid is above the 1/3 probe….NOTE, these probes are studs or cooper rods into the interior of the tank.  So, the liquid, even the GRAY tank, is conductive.  SO the 1/3 probe is in the liquid….and the bottom probe is in the liquid.  The liquid makes the circuit.  BINGO.  1/3 light is on…..repeat for 2/3 & FULL.  This is a CONDUCTIVE circuit….  It you jumpered the bottom Probe and either of the TOP (not in the liquid)….you’d get a LIGHT.

THE REASON they are NOT accurate.  This is a CHEAP system.  The tank has an internal buildup of feces and bacteria and toilet paper.  Think of it as a SLUDGE or SLIME that has coated the inside.  So, when you have new or fresh liquid in the tank, this dried out sludge becomes conductive.  Then the liquid wicks up the sludge.  So, the ACTUAL liquid level is say at 1/4 height.  But when you drive…..that liquid sloshes around.  That resaturates the crud or buildup.  That then makes a circuit from the 1/3 probe to the bottom one. BINGO….light is on.  NOW….let it sit overnight or even for a day or two.  YES, you continue to add liquid.  BUT the tank crud will dry out.  It takes agitation (like driving) to slosh it up and around.  NOW….this is a COMMON problem in Municipalities.   They buy special probes as well as a high voltage transformer. 600 VAC burns or arcs and destroys “floating objects” or wads of TP. THAT is how they really KNOW the level.  If we had a HIGH VOLTAGE system….the “crap” or crud would burn off (in a circle) and stay clean.  Our probes would only measure the PURE liquid.

FINALLY….hope this explains all the “tricks” and procedures that folks use or were mentioned here.  You HAVE to have a fairly CLEAN interior area around where a sensor is located.  With the Techma, the middle is expected to have a buildup. Good backflush and the use of a cleaner that has a surfactant (which coats or has “sheeting” additives ). THINK about your dishwasher. MOST have a “Rinse Aid” or a surfactant dispenser.  So, the final rinse is dosed with the RINSE AGENT.  That helps sheet off water and also helps eliminate water spotting.  Let it run out or say…..NOT NEEDED….your dishes will have more water on them or spots.  I had to sort of “teach” a bit of chemistry to my wife.  We finally LOST our 25 YO high end GE.  She complained about its cleaning and such.  I filled the new Kitchen Aid’s rinse agent reservoir.  NOW, the KA’s design and technology is a world ahead.  The dishes sparkle.  The SS flatware is SHINY…she emptied the drawer and glasses shelf and dishes and ran every.one,

THEN, I quizzed her.  She had decided the Rinse Aid was just a gimmick and not used it in years….  OMG….that was ONE of the contributors to poor performance.  She NOW has me check it.

SO…..THEORY.  If you “doused” your black tank with a tablespoon of dishwasher Rinse Aid….when you mixed up your “chemicals”….you MIGHT find that the crap would NOT build up as much.  There are formulas on the Internet for the GEOMETHOD.  They use detergents and waster softeners.  The “theory” is that if you can attack or breakdown the crud on the side….then the liquid will NOT WICK up.

NOW…if the comment that the HIGH Sensor on the TECMA is in a section of the tank where there is NO backflushing or the buildup is severe….move it.

As to the SeeLevel.  The sensor that they use is a LONG PCB. You order it for the height of your tank.  It provides a variable “capacitance” signal.  When the tanks gets dirty….you can recalibrate….but, there is only so much or thickness of crud or buildup it can tolerate or handle.  Many, and we have had a bunch, will post…”IT DON’T WORK”.  SeeLevel says.  CLEAN and RECLEAN per instructions.  Once stable and the adjustment or calibration is within the normal range…..use…but you MUST periodically  clean the tanks…


 

[amphi_sc]

When my Tecma Silence tank sensors act up I give the black tank an enema using a modified Camco tornado flush 

https://www.campingworld.com/tornado-permanent-tank-rinser-with-remote-connection-28091.html

I cut/broke off the flange so I could shove it up the black tank and let it blast away ... catching what I could as the scale & stuff comes out. Push the hose up and back letting it bang around a lot.  When I think it is done I fill the tank with fresh water and drain the tank a few times.  Rinse and repeat as they say... sensors act fine again for a few months.

Also, as a routine practice I leave about 10-20% water in the tank as I drive to the next CG allowing it to slosh... and then drain as I arrive in the CG.

In the past I had tried various "magic" concoctions but occasional use of the Tornado has been the best solution.

YMMV

[Tom Cherry]

10 hours ago, amphi_sc said:

When my Tecma Silence tank sensors act up I give the black tank an enema using a modified Camco tornado flush 

https://www.campingworld.com/tornado-permanent-tank-rinser-with-remote-connection-28091.html

I cut/broke off the flange so I could shove it up the black tank and let it blast away ... catching what I could as the scale & stuff comes out. Push the hose up and back letting it bang around a lot.  When I think it is done I fill the tank with fresh water and drain the tank a few times.  Rinse and repeat as they say... sensors act fine again for a few months.

Also, as a routine practice I leave about 10-20% water in the tank as I drive to the next CG allowing it to slosh... and then drain as I arrive in the CG.

In the past I had tried various "magic" concoctions but occasional use of the Tornado has been the best solution.

YMMV

AMEN to that. Others have jury rigged wands or such and also did an “aggressive internal cleansing”.  Pity there is no magic chemical mix that will “cleanse” the black tank….like those of us on 5 year screenings do for the colonoscopy.  That would solve it.

I DO wonder if a $2 bottle of a rinse aid, dumped in with maybe 10-15 gallons of water and the “usual” tank additive…..might be beneficial.  ASSUMING you drive to the CG and get the inner walls totally saturated.  That will not do any collateral damage and if it keeps the buildup at bay?.?…GREAT.

Thanks for reinforcing my comments….

[Tom Miller]

I recently had this issue and after repair was coupled it turned out to be debris caught in the macerating section of the toilet.

repairs were by Jeff Bleakly formerly of Integrity RV

 

[Bobbyboy]

16 hours ago, Tom Cherry said:

Catching up.  Great comments and such.  Bottom line.

The sensors on a typical Monaco control panel or such are 12 VDC circuits.  There are 4 sensors.  One at Bottom is “NEG” or ground.  The 1/3; 2/3 & full are the POS.  Now it may be reversed…. Bottom line.  When the liquid is BEOLW 1/3…..there is NO LIGHT.  But when the liquid is above the 1/3 probe….NOTE, these probes are studs or cooper rods into the interior of the tank.  So, the liquid, even the GRAY tank, is conductive.  SO the 1/3 probe is in the liquid….and the bottom probe is in the liquid.  The liquid makes the circuit.  BINGO.  1/3 light is on…..repeat for 2/3 & FULL.  This is a CONDUCTIVE circuit….  It you jumpered the bottom Probe and either of the TOP (not in the liquid)….you’d get a LIGHT.

THE REASON they are NOT accurate.  This is a CHEAP system.  The tank has an internal buildup of feces and bacteria and toilet paper.  Think of it as a SLUDGE or SLIME that has coated the inside.  So, when you have new or fresh liquid in the tank, this dried out sludge becomes conductive.  Then the liquid wicks up the sludge.  So, the ACTUAL liquid level is say at 1/4 height.  But when you drive…..that liquid sloshes around.  That resaturates the crud or buildup.  That then makes a circuit from the 1/3 probe to the bottom one. BINGO….light is on.  NOW….let it sit overnight or even for a day or two.  YES, you continue to add liquid.  BUT the tank crud will dry out.  It takes agitation (like driving) to slosh it up and around.  NOW….this is a COMMON problem in Municipalities.   They buy special probes as well as a high voltage transformer. 600 VAC burns or arcs and destroys “floating objects” or wads of TP. THAT is how they really KNOW the level.  If we had a HIGH VOLTAGE system….the “crap” or crud would burn off (in a circle) and stay clean.  Our probes would only measure the PURE liquid.

FINALLY….hope this explains all the “tricks” and procedures that folks use or were mentioned here.  You HAVE to have a fairly CLEAN interior area around where a sensor is located.  With the Techma, the middle is expected to have a buildup. Good backflush and the use of a cleaner that has a surfactant (which coats or has “sheeting” additives ). THINK about your dishwasher. MOST have a “Rinse Aid” or a surfactant dispenser.  So, the final rinse is dosed with the RINSE AGENT.  That helps sheet off water and also helps eliminate water spotting.  Let it run out or say…..NOT NEEDED….your dishes will have more water on them or spots.  I had to sort of “teach” a bit of chemistry to my wife.  We finally LOST our 25 YO high end GE.  She complained about its cleaning and such.  I filled the new Kitchen Aid’s rinse agent reservoir.  NOW, the KA’s design and technology is a world ahead.  The dishes sparkle.  The SS flatware is SHINY…she emptied the drawer and glasses shelf and dishes and ran every.one,

THEN, I quizzed her.  She had decided the Rinse Aid was just a gimmick and not used it in years….  OMG….that was ONE of the contributors to poor performance.  She NOW has me check it.

SO…..THEORY.  If you “doused” your black tank with a tablespoon of dishwasher Rinse Aid….when you mixed up your “chemicals”….you MIGHT find that the crap would NOT build up as much.  There are formulas on the Internet for the GEOMETHOD.  They use detergents and waster softeners.  The “theory” is that if you can attack or breakdown the crud on the side….then the liquid will NOT WICK up.

NOW…if the comment that the HIGH Sensor on the TECMA is in a section of the tank where there is NO backflushing or the buildup is severe….move it.

As to the SeeLevel.  The sensor that they use is a LONG PCB. You order it for the height of your tank.  It provides a variable “capacitance” signal.  When the tanks gets dirty….you can recalibrate….but, there is only so much or thickness of crud or buildup it can tolerate or handle.  Many, and we have had a bunch, will post…”IT DON’T WORK”.  SeeLevel says.  CLEAN and RECLEAN per instructions.  Once stable and the adjustment or calibration is within the normal range…..use…but you MUST periodically  clean the tanks…:
 

Tom:  Good explanation of sensors to determine the levels in the Black Tank---but are those the same sensors that give the "red light" warning on the Tecma flush buttons?

or does the Tecma have its own different sensors?  The conversation started with  the Tecma sensors and how to bypass them then merged into the "capacity" sensor discussion.   did I miss something along the way.

 

Bob L, 08 dynasty

[birdshill123]

There are 2 RV proctologists at Q every year. Expensive but apparently they clean the tank until it is like new.

[Frank McElroy]

2 hours ago, Bobbyboy said:

Tom:  Good explanation of sensors to determine the levels in the Black Tank---but are those the same sensors that give the "red light" warning on the Tecma flush buttons?

or does the Tecma have its own different sensors?  The conversation started with  the Tecma sensors and how to bypass them then merged into the "capacity" sensor discussion.   did I miss something along the way.

 

Bob L, 08 dynasty

Tecma has its own two sensors that stick onto the side of the tank.