Replacing controller for Tecma macerating toilet

Our motorhome has two toilets; an electric gravity toilet in the half bath, and an electric macerating toilet in the rear bathroom. Both have had their issues; in 2021 I needed to replace the flush switch on the half bath toilet, and in 2022 I needed to dismantle the rear toilet to clear out a blockage.

Recently, the rear toilet stopped working again, in much the same way as before, so I figured that I needed to clear a blockage again. Though it was a bit different this time; it would flush first thing in the morning, then stop working again. Which made me think something else was going on. Upon dismantling it, I confirmed that there wasn’t any blockage. Research indicated that the issue was likely the controller unit; apparently our vintage had a known issue where it could overheat and stop working.

So, I ordered a replacement controller. It’s the “Thetford 36398 Toilet Controller for Tecma Silence Plus RV Toilet”. I purchased it from Boat & RV Accessories, as they had it for a good price and could ship it overnight. But it is also available on Amazon from a couple of sellers.

But unfortunately this did not solve the issue. I thought it did, as the toilet worked properly for a few days, but yesterday as we prepared to leave our campsite, it failed again. It’s possible that the new controller went bad, but it seems much more likely to me that the macerator pump is actually the cause. So I guess I need to try replacing that.

On to the pictures. Here’s the toilet in the shower, prior to looking for clogs:

Paladin sniffing the sewer pipe:

I looked where the blockage was before, after the macerator, but it was clear:

So I fully removed the macerator; no blockage anywhere:

The suspect controller:

Work in progress:

The new controller arrived, and even included a copy of the manual:

I put the toilet back in the shower (it had been back in place, though disconnected, while I waited for the part), and removed the old controller:

I added the new controller, and re-installed the macerator:

Then re-installed the toilet, and checked it:

It worked for a few days, but as mentioned above, replacing the controller didn’t solve the issue. Stay tuned for a future post on my next attempt at repairing this toilet! We’re very glad that we have two toilets in our coach, so can make do with using the other one in the meantime.

Just another super glamorous aspect of RV life.