Chromagen Solar No Hot Water — Fix Guide

What Does This Error Mean?

Check the controller for any displayed error codes first — E1, E2, or LO indicate a specific fault. If no code shows, the pump may have stopped circulating water or there may be an airlock in the pipes. On an overcast day, no hot water is normal — the backup electric boost element should still heat if it is enabled.

Affected Models

Chromagen CR Series
Chromagen Optima
Chromagen Crown
Chromagen Prisma

Common Causes

Cloudy or cold weather reducing solar gain below usable level
Circulation pump stopped or failed
Airlock in the collector or pipe loop
Sensor fault triggering a protective shutdown (E1, E2, or LO code)
Boost/backup electric element disabled or faulty
Pressure relief valve open and losing water

How to Fix It

Check the controller for error codes.

E1 = upper sensor, E2 = lower sensor, LO = overheating cutout, PUMP = pump fault. Fix the specific error first before expecting hot water to return.
Verify the boost element is enabled.

The Chromagen controller has a boost setting for the backup electric element. If it is off or on a timer, the system will not heat when solar input is insufficient. Enable boost manually and wait 30–60 minutes.
Check the pump is running.

During daylight hours, place your hand on the pipes near the pump — one should be warm (outgoing) and one cool (returning). If both are cold, the pump is not circulating. This requires a technician.
Bleed the system for airlocks.

An airlock stops water circulating even if the pump works. A technician can bleed the system via the air vent on the collector or pipe loop.
Check for visible leaks.

Look at the pressure relief valve outlet (usually a pipe near the tank). If water is dripping, pressure is too high or the valve is faulty — both need a plumber.

When to Call a Professional

If no error code is shown but there is still no hot water after sunny days, the pump or circulator is likely faulty and needs a qualified solar technician.

Frequently Asked Questions

Is it normal for a Chromagen solar heater to have no hot water on a cloudy day?

Yes, on heavily overcast days solar input can be too low to heat the tank. The backup electric boost element should compensate — check it is enabled on the controller.

Hot water worked fine yesterday — why nothing today?

A sudden loss is usually a pump fault, a tripped circuit breaker on the boost element, or a pressure event that triggered the relief valve. Check the controller display first.