Looking for the Replacement Flush Valve for a Thetford Toilet Model 42053
Updated 08/06/2026 | Published 08/01/2026
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Question:
Looking to replace the flush valve on my Thetford model 42053 toilet. Your part number TH78SA comes up, but the description does not include compatibly with the 42053. Will this work?
asked by: Joe B
Expert Reply:
Happy to help Joe, thanks for reaching out!
Yes, the Replacement Water Valve will work with your Thetford model 42053.
The product description doesn't currently list model 42053, but the 42053 is a Aqua Magic Style II toilet, and # TH78SA is the correct replacement water valve for Aqua Magic Style II models like # TH49FR. Thetford identifies replacement water valve 42049 in the instruction guide for the Aqua Magic Style II product line.
Did you install your Thetford toilet on an RV, boat or trailer?
Kurt N.
8/6/2026
The parts worked for me. However, when I had everything disconnected I noticed that the plastic ball valve (not included in the kit) was rough and pitted. The plastic part rubs against the smooth black flexible seal. I should have purchased a new plastic ball valve, but I was staying in the RV and did not want to wait for the part to be delivered before I put everything back together. I reused the old plastic ball part. Now, sometimes I notice that water seeps down and out, probably because the plastic ball part is not smooth. Eventually I will have to take everything apart again to put a new plastic ball valve in. I suggest that you examine the plastic ball valve and if it is rough and pitted, get a new one before you take everything apart.
James D.
8/6/2026
Product Page this Question was Asked From
Replacement Water Valve for Thetford Aqua-Magic Style II RV Toilet - Restores Flush Power - Qty 1
- Accessories and Parts
- RV Toilet
- Valves
- Water Valve
- Thetford
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Rick D.
8/6/2026
It worked just fine for me ezpz.