⚡ Quick Answer (Start Here)
If your instant heater has any issue:
❌ No hot water
🌡 Not hot enough
⚡ Power not working / tripping
💡 Red or Green Light on Heater is not Functioning Properly
🚿 Weak or strong water flow
💧 Leaking
👉 The problem usually falls into 3 main categories:
Power / Electrical issue
Water flow / shower setup issue (Instant Heater used as a closed outlet)
Internal component issue
🔍 Step 1: Identify the Problem
🚫 1. No Hot Water at All
🚫 1. No Hot Water at All
Possible Causes:
Power supply OFF
No Water Flow at all
Flow too weak to trigger heating
Faulty heating element
Quick Checks:
Is power switch ON?
Is water flowing enough?
Any indicator lights?
👉 If water flow is ok and no red or green light and no heat at all → likely external electrical fault. Please get an Licensed Electrical Worker (LEW) to have it checked before contacting our service hotline
👉 If water flow is ok and there is red or green light BUT no heat at all → proceed to contact our service hotline
🌡 2. Water Not Hot Enough
🌡 2. Water Not Hot Enough
Possible Causes:
Flow rate too high (very common)
Shower head too big (recommend to use the same showerhead provided with your instant heater)
Power Setting set too low (turn the settings to maximum)
Incoming water too cold (some times on a rainy day)
Did not install the SVF valve provided in every instant heater
Key Insight:
👉 Instant heaters heat on the spot
→ More flow = less heating
→ Instant Heaters do not have a fixed temperature output as it depends on your incoming water temperature unlike storage water heaters.
✅ Fix:
Reduce water flow rate with the provided SVF valve. There is a smaller knob that can control the flow rate of the incoming.
Use the given JOVEN branded shower head that came with your purchase
Consider upgrading to a storage water heater if the temperature is inadequate
⚡ 3. Heater Trips Power
⚡ 3. Heater Trips Power
Possible Causes:
Electrical leakage
Faulty heating element
Moisture ingress
Wiring issue
⚠️ Important:
Do NOT keep resetting
Switch OFF immediately
👉 Requires inspection. If this is a new installation, please look for your installer.
If you have been using the heater for some time, please look out for any burning smells or even faulty external electrical connections and contact a Licensed Electrical Worker (LEW) for repairs. However, if you are unable to locate the cause of the trip, do contact our service hotline for assistance.
💡 Red or Green Light on Heater is not Functioning Properly
💡 Red or Green Light on Heater is not Functioning Properly
Causes:
Incorrect incoming voltage of 230V
Water flow is not turned on
Internal Component Malfunction
✅ Fix:
Check the incoming voltage is 230V (Licensed Electrical Worker can do it)
When there is incoming power supply the Green light will turn on. When there is water flowing through and the heater is turned on, the red light should turn on and you should have heated water flowing out from the heater.
Contact our service hotline if you have checked the above steps.
🚿 4. Water Flow Issues
🚿 4. Water Flow Issues
Causes:
Blocked filter / shower head
Low water pressure
Inlet blockage
✅ Fix:
Check the SVF valves or the valves connected to the heater is functioning and not choked
Disconnect the inlet to the Instant heater and check if the water flow from the incoming mains is ok
💧 5. Water Leaking
💧 5. Water Leaking
Check Where Leak Comes From:
Location | Meaning |
Pipe connection | Loose fitting or missing O-Ring Installed |
Heater inlet/outlet | Missing O-Ring Installed (Please install the O Ring provided) |
Heater body | Internal leaking issue |
👉 Body leak → stop use immediately and turn the power off. Where possible verify the source of leak and take a video and contact our service staff.
⛓️💥 6. Instant Heater Installed as a Closed Outlet
JOVEN Instant Heater Installed for Multiple Points? This May Be Unsafe
⚡ Quick Answer (Read This First)
If your instant heater is:
Connected to multiple outlets (shower + sink)
Installed with mixer taps / concealed piping
Used like a storage heater system
👉 But your heater is an open outlet type
⚠️ This is incorrect installation and can be unsafe
🔍 What is an Open Outlet Instant Heater?
Open outlet heaters:
Designed for single point use only
Connected directly to shower head
Not designed to handle back pressure
👉 Most bathroom instant heaters in Singapore are open outlet type
🔒 What is a Closed Outlet (Multipoint) System?
Closed outlet systems:
Supply water to multiple taps
Use mixer taps / concealed piping
Operate under pressure
👉 Requires a different type of heater design
🚨 What Happens If Installed Wrong?
⚠️ 1. Pressure Build-Up (DANGEROUS)
Open outlet heater is not designed for pressure
Back pressure can damage internal components
⚠️ 2. Temperature Instability
Sudden hot/cold fluctuations
Poor user experience
⚠️ 3. Heater Malfunction
Heating becomes inconsistent
Unit may shut down or fail
⚠️ 4. Leakage or Internal Damage
Seals and internal parts may fail
🧠 Key Principle (MOST IMPORTANT)
👉 Instant heater performance depends on:
⚡ Power (kW)
🚿 Water Flow
💧 Water Pressure
If mismatch happens → heater will underperform
🚫 What You SHOULD NOT Do
❌ Open heater casing
❌ Modify wiring
❌ Use incompatible shower system
❌ Ignore electrical issues
💡 Why JOVEN Instant Heaters Perform Better
✅ Stable heating system
✅ Designed for optimal flow control
✅ Built-in safety protections
👉 But correct installation & setup is still critical
📅 Need Help Diagnosing?
Prepare:
📸 Photo/ Video of heater & shower setup
📍 Postal code
📝 Description of issue
👉 We can quickly identify:
flow mismatch
power issue
installation problem
Do take note of these service conditions before requesting an appointment:
Check if your heater has a valid warranty otherwise a prepayment transport fee is chargeable.
If we found any external electrical faults, no repairs will be done and there will be a diagnostic fee of $70/$85 (depending on area). We recommend you to approach a certified Licensed Electrical Worker (LEW) to check on your external wiring before contacting us to arrange for an appointment.
❓ Frequently Asked Questions
Why instant heater water becomes cold suddenly?
👉 Flow too strong or pressure unstable
Can I use rain shower with instant heater?
👉 Only for selected JOVEN instant heater models
Which is better: reduce flow or upgrade heater?
👉
Quick fix → reduce flow
Best solution → upgrade to Storage Heater for more consistent temperature