FAQ
TL;DR: Typical fix for a no‑heat Kospel Twister is replacing a burnt flow microswitch (~PLN 20). “burning a microswitch is not accidental.” [Elektroda, mawerix123, post #16930822]
Why it matters: This FAQ helps DIYers diagnose no‑heat and low‑pressure faults fast, before costly part swaps.
Quick Facts
- Model discussed: Kospel Twister instant heater, 3.5 kW rating noted by the user. [Elektroda, Chlebuś, post #16930619]
- Low water pressure can stop the flow valve from engaging the heater switches. [Elektroda, stanislaw1954, post #16930691]
- First checks: heater continuity with an ohmmeter and diaphragm tap reaction. [Elektroda, retrofood, post #16930671]
- Common failure point: burnt microswitch; replacement part costs about PLN 20. [Elektroda, mawerix123, post #16930822]
- Proven field fix: swapping the entire heating unit restored operation. [Elektroda, Chlebuś, post #16935954]
Why won’t my Kospel Twister heat when water pressure is low?
Low pressure may not open the flow valve enough to trigger the heater’s switches. Without switch engagement, heating stays off. Restore adequate pressure or reduce flow restrictions before deeper diagnostics. This symptom directly links to the unit’s flow‑activated switching. [Elektroda, stanislaw1954, post #16930691]
What multimeter checks should I start with on a no‑heat Twister?
Start with a continuity check of the heating element using an ohmmeter. Then verify the unit reacts when you open the diaphragm tap and that the needle actually switches the heater contacts. These two checks isolate many simple electrical and flow faults. [Elektroda, retrofood, post #16930671]
Which part is the black switch and what does it do?
The black round element is the flow actuator that drives the heater’s microswitch contacts. Water flow moves a needle that then toggles the switches on the right side. If flow is insufficient or the switch is damaged, the heater will not energize. [Elektroda, stanislaw1954, post #16930760]
Could a failed microswitch explain soot or burn marks on the housing?
Yes. Users observed burn marks aligned with a lower end switch, and experts flagged power control damage, like a failed microswitch, as a cause. “Lack of heating could be caused by damage to the power control system.” Inspect and replace the microswitch if burnt. [Elektroda, retrofood, post #16930710]
How much does a replacement microswitch cost and is repair worth it?
A microswitch costs about PLN 20. However, a burnt switch is cause or effect. Diagnose the root issue before replacing parts. If more components have failed, full repair might not be economical compared to replacing the assembly. [Elektroda, mawerix123, post #16930822]
Do freezing temperatures affect performance, or is it a red herring?
Colder inlet water during severe frost reduces outlet temperature rise. The heater still works, but water feels cooler. Low pressure is the real trigger that can stop the flow switch and block heating entirely. Address pressure first. [Elektroda, stanislaw1954, post #16930691]
How do I test whether the flow mechanism is engaging?
Open the diaphragm tap and observe whether the needle travels and switches the heater contacts. If the needle does not move or contacts stay open, the flow system or switch needs service. This quick test confirms the hydraulic trigger path. [Elektroda, retrofood, post #16930671]
Can deaeration bring heat back temporarily?
Yes. One user restored heating for several hours after deaeration. Air pockets can block flow actuation, so bleeding helps briefly. If the symptom returns, inspect the microswitch and flow components for underlying faults or partial blockages. [Elektroda, Chlebuś, post #16930619]
Why did my heater suddenly start working after a delay?
Intermittency happens. A user reported the indicator lighting and heat returning after 5 seconds on a later try. That suggests marginal flow actuation or sticky switch contacts. Clean, adjust, or replace the microswitch and verify pressure. [Elektroda, Chlebuś, post #16933463]
Is replacing the whole heating unit a valid fix?
Yes. Swapping a complete heating assembly from a similar heater restored normal operation for the user. This bypassed uncertain component‑level faults. Use an identical or compatible unit and recheck seals and electrical connections. [Elektroda, Chlebuś, post #16935954]
What does soot on the housing usually indicate on this model?
Soot or darkening opposite the lower end switch suggests localized overheating or arcing at that switch. Visual evidence pointed to the lower switch being the affected part. Replace the switch and inspect wiring and terminals for heat damage. [Elektroda, osiniak75, post #16930690]
Where exactly are the burn marks relative to the mounting holes?
Reports note the housing blackened centrally opposite the lower end switch. Screw holes appear on both sides, which can confuse orientation. Focus on the area aligned with the lower switch when inspecting scorch patterns. [Elektroda, osiniak75, post #16930739]
Quick 3‑step: how do I safely troubleshoot no‑heat?
- Isolate power, remove cover, and measure heater continuity with an ohmmeter.
- Restore water, open the diaphragm tap, and confirm the needle switches contacts.
- If no actuation or arcing signs appear, replace the microswitch and retest.
[Elektroda, retrofood, post #16930671]
When should I replace instead of repair individual parts?
If the microswitch burned and other components show heat damage, replacement may be uneconomical. One expert advised finding the cause first because a burnt switch can be cause or effect. Consider a complete heating unit swap to save time. [Elektroda, mawerix123, post #16930822]
