Wcooper04
01-10-2026, 09:09 PM
Posting this to share my recent Aquahot repair journey. A few months ago my water temp would drop and pressure would fall. Installed new tempering valve and it was fixed….for a couple of months. Replaced tempering valve a second time (hoping I had been unlucky) and did not fix symptoms. Long story short - here’s what I did and each thing helped symptoms:
1. Tempering valve
2. Flushed system with vinegar (used a sump pump and let vinegar spill from one bucket into another to let sediment settle out). Did this for about 4 hours. Got a good deal of sediment out of system. This was only a flush of Aquahot system, not entire water system.
3. Replaced shower head and faucet. (Use 1.5gpm faucets per Aquahot)
4. Cleaned screens in sinks.
5. Replaced radiator cap on Aquahot. Rubber under it was cracked - not enough to ever have a visible leak, but enough to allow fluid to come out, lay on top and evaporate before ever being seen.
6. Found small crack in reservoir tank that wasn’t noticeable unless tank was filling. Replaced tank.
7. Ran hot water/heaters for several hours to monitor and refill transfer fluid when hot (measuring reservoir tank when cold is evidently pointless).
8. Adjusted tempering valve DOWN to have approx 125 degree water when wide open on hot.
Took a few days for me to stumble through this, but the point is - it may not just be ONE thing wrong. For me, it was a series of small things….and now…..limitless hot water!
I’ve gotten a good deal of knowledge POG and just wanted to put this out there for anyone that needed a semi-comprehensive list of troubleshooting items.
Thanks,
Wes Cooper
2003 Royale
1. Tempering valve
2. Flushed system with vinegar (used a sump pump and let vinegar spill from one bucket into another to let sediment settle out). Did this for about 4 hours. Got a good deal of sediment out of system. This was only a flush of Aquahot system, not entire water system.
3. Replaced shower head and faucet. (Use 1.5gpm faucets per Aquahot)
4. Cleaned screens in sinks.
5. Replaced radiator cap on Aquahot. Rubber under it was cracked - not enough to ever have a visible leak, but enough to allow fluid to come out, lay on top and evaporate before ever being seen.
6. Found small crack in reservoir tank that wasn’t noticeable unless tank was filling. Replaced tank.
7. Ran hot water/heaters for several hours to monitor and refill transfer fluid when hot (measuring reservoir tank when cold is evidently pointless).
8. Adjusted tempering valve DOWN to have approx 125 degree water when wide open on hot.
Took a few days for me to stumble through this, but the point is - it may not just be ONE thing wrong. For me, it was a series of small things….and now…..limitless hot water!
I’ve gotten a good deal of knowledge POG and just wanted to put this out there for anyone that needed a semi-comprehensive list of troubleshooting items.
Thanks,
Wes Cooper
2003 Royale