Thetford Toilet Possessed

[Kxbronco]

I’m having a problem with my Thetford Aqua Magic Residence toilet model # 42169 in my 2005 Allegro Bay 34XB. It works exactly as it is supposed to except when I’m filling my fresh water tank and water is running/leaking into the toilet bowl. The pedal is in up/off position. It only does this when filling the tank. Once the tank is full and I turn off the water going to the motorhome it stops. When I turn the pump on, no water comes out. When I connect to city water, no water comes. When I step on the pedal, it works just like it is supposed too whether on pump or city water. Water shuts off when I release the pedal.

Anybody got any ideas as to what the problem might be? I’m thinking the water valve in the toilet, but why does it leak only when filling the fresh water tank?

[Old-Biscuit]

While filling your fresh water tank IF you open a faucet does it stop the water from going into toilet????

Fill Valve could be leaking thru causing Low pressure on the Cold water system...toilet valve is weak and low pressure allows water to leak thru into toilet.
Full pressure from pump/city water keeps toilet valve closed
**Just my theory cause Fill Valve can cause strange things to occur in RV Water System


Replace the toilet valve and be done with it --- it's 18 yrs old

[Kxbronco]

Thanks for the reply O-B. With the tank empty, I started filling the tank. Looked at the toilet and some water was flowing in. Turned on a faucet and got some water and air and the toilet continued to have water flowing in.

Toilet was completely replaced approx 7 yrs ago or so.

When you say fill valve, I assume you are talking about the valve in the toilet, correct?

Another question. Should there be water/air coming thru a faucet while filling the tank? I’ve never had a reason to open a faucet while filling the tank.

Originally Posted by Old-Biscuit

While filling your fresh water tank IF you open a faucet does it stop the water from going into toilet????

Fill Valve could be leaking thru causing Low pressure on the Cold water system...toilet valve is weak and low pressure allows water to leak thru into toilet.
Full pressure from pump/city water keeps toilet valve closed
**Just my theory cause Fill Valve can cause strange things to occur in RV Water System


Replace the toilet valve and be done with it --- it's 18 yrs old

[Old-Biscuit]

Fill Valve.......valve you open to put water in fresh water tank using a hose connection.

Air/water sputtering from a faucet when filling means 'Fill Valve' is leaking thru allowing water into the RV Plumbing lines

'Fill Valve'......diverts City Water to fresh water tank.
City Water line connects to Cold Water Line....same as Pump Discharge Line
'Fill Valve' not fully closing will allow water to go into the City Water Line (Cold water system)

New fill valve and toilet valve