What this is
The genuine Rheem solar differential controller retrofit kit, part number 299174, for direct LoLine solar water heaters. 🚚 Special Order Item – Ships in 3-5 Business Days
⚠ Check the date first. This kit suits Rheem, Solahart and Edwards VE direct LoLine solar water heaters manufactured before 23 January 2007. If your system was made on or after that date, this is the wrong kit.
The date is the whole question on this part. Send us the model and serial number from your tank data plate and we will confirm before you order — email sales@solarhotwaterparts.com.au.
This is a controller, not a pump
This kit replaces the differential controller. It does not include a circulating pump.
If your pump has failed as well — or if the pump and controller on your system are combined in a single housing, which is how later LoLine systems are built — you need the Rheem Loline Solar Pump & Controller Kit 299293 instead.
What the part number means
Rheem call this “Kit Service Diff Controller 511 Ser”, which is how it appears on an invoice and in their catalogue. 511 is the LoLine tank series — for example model numbers 511271 and 511325. Diff Controller is short for differential controller: the unit that compares the collector temperature against the tank temperature and decides when to run the pump.
When you need it
- Controller dead, or not switching the pump on
- Collectors hot while the tank stays cold, with a pump that runs when powered directly
- Display or solar monitor not lighting
Ordering
🚚 Special order item — ships in 3–5 business days.
This item must be installed by a licensed tradesperson.