Alto-Shaam CT Express Combi Error Code E105: Low Water Pressure
E105 Low Water Pressure means low or no water pressure is reaching the oven. Check that the water supply is connected and on, and call for service if it returns.
Medium: steam and rinse functions are lost until the pressure switch closes.
- Code
- E105
- Maker
- Alto-Shaam
- Equipment
- Combi ovens
- Applies to
- CT Express 4-10ESi, 4-10ESiVH, 4-10CCi, CTX4-10E, CTX4-10EC, CTX4-10EVH
What does Alto-Shaam error code E105 mean?
The CT Express needs water for steam, rinsing and cleaning, and a pressure switch confirms it is present. When the switch does not close, the control posts E105 Low Water Pressure. The manual lists five causes: the water supply is not connected or is off, the water pressure is too low, the solenoid valve is not energized or not opening, the pressure switch is defective, or there is a poor connection at the pressure switch or relay board. Its actions are to check the supply connection, the pressure, the solenoid and the pressure switch. The first two are things an operator can look at. The last three need a technician with a meter. Because the switch only reports whether pressure is present, a good supply and a bad switch give the same message as a closed valve. This number is specific to the CT Express in this form. CT PROformance and Classic ovens use E105 as No or Low Water Pressure with a shorter list.
Affected models and control systems
CT Express ovens, namely 4-10ESi, 4-10ESiVH, 4-10CCi, CTX4-10E, CTX4-10EC and CTX4-10EVH.
Code numbers and their meaning can change between control generations. We match the full model and control before acting on a code.
What you may notice
- E105 Low Water Pressure on the display
- Steam or rinse functions not starting
- Weak water flow at the inlet hose
Possible causes
Listed in Alto-Shaam's documentation
- Water supply not connected or off
- Water pressure too low
- Solenoid valve not energized or not opening
- Pressure switch defective
- Poor connection at the pressure switch or relay board
Other likely causes — what usually sits behind error code E105 on this control. A technician confirms which one it is before any part is replaced.
- A filter or inlet screen clogged by sediment after maintenance on the building's water line
- A water softener bypass left half open that reduces flow
Safe checks before calling for service
- Check that the water shutoff valve behind the oven is fully open.
- Look at the hose for kinks and check that the filter is not due.
- Turn the oven off and on once.
- If E105 returns, tell the technician whether other taps in the kitchen have normal pressure.
How a technician diagnoses error code E105
- Read the code and confirm the supply connection.
- Measure water pressure at the oven inlet.
- Check that the solenoid valve is energized and opens.
- Test the pressure switch and its connection to the relay board.
- Replace the valve or switch that fails.
- The solenoid and pressure switch are wired to the relay board with live voltage.
- Pressure and flow need a gauge at the oven inlet.
- A weak connection at the relay board is not visible from outside.
How error code E105 differs from similar codes
The CT PROformance and Classic ovens also use E105 for water pressure; the CT Express list adds the solenoid valve and the connections as causes.
Technical reference
- Document
- Combitherm CT Express Technical Manual (4-10ESi, 4-10ESiVH, 4-10CCi, CTX4-10E, CTX4-10EC, CTX4-10EVH)
- Maker documentation
- Alto-Shaam owner support
- Edition
- MN-36008 (Rev. 9) 03/16
- Models / control
- CT Express 4-10ESi, 4-10ESiVH, 4-10CCi, CTX4-10E, CTX4-10EC, CTX4-10EVH
- Section
- Section C, Error Codes, pp. C-3 to C-8
- Checked
- October 2026
We use the maker's document to read the code and do not reproduce it. Always confirm the complete model and control before applying these steps.
Related Alto-Shaam combi oven error codes
Does E105 always mean the water is off?
Often, but a defective switch gives the same message.
Will the oven cook?
Functions that need water will not run.
Is the solenoid involved?
Yes, a solenoid that does not open is one of the five causes.
Need help with Alto-Shaam error code E105?
A technician confirms the cause on site and gives you the price in writing before any work starts.