23
K
ΔT
With KC model, available DHW litres per minute depend on boiler heat output and water mains supply temperature, according to the following
formula:
l = DHW litre per min. = --------
where K is:
- 264 in KC 12 model
- 402 in KC 24 model
- 465 in KC 28 model
- 489 in KC 32 model
ΔT = hot water temperature – cold water temperature
For instance, with model KC 24, if the supplied water is at 8°C and you want shower water at 38°C, the value of ΔT is:
ΔT = 38°C - 8°C = 30°C
and the number of DHW litres per minute available at 38°C is:
402
l = ------ = 13.4 [litres per minute] (water mixed at cock)
30
1.14.4. CoMfoRT function (for KC model only)
The "COMFORT" function can be enabled on models of the Itaca range by pressing the relevant button on the display. This function keeps the plate
heat exchanger hot, reducing waiting time for the production of DHW.
1.14.5. ANTI-fReeZe function
This boiler is fitted with an anti-freeze protection system, which works when the following functions are activated: OFF/SUMMER/WINTER/CH ONLY
The anti-freeze function only protects the boiler, not the whole heating system.
The central heating system can be effectively protected against icing by using specific anti-freeze products that are suitable for multi-metal
systems.
Do not use anti-freeze products for car engines, and check the effectiveness of the product used over time.
In case burner cannot be ignited due to the lack of gas, the anti-freeze functions are anyway enabled through the circulation pumps.
1.14.5.1. Ambient probes anti-freeze function
If the boiler board is OFF, or DHW ONLY, and the ambient probes detect a temperature below 5°C, a heating request to heat the probe-controlled
room is launched. The heating function ends when the probe ambient temperature reading reaches 6°C.
1.14.5.2. flow anti-freeze function
When the heating water temperature sensor detects a water temperature of 5°C, the boiler switches on and stays on at its minimum heat output
until the temperature reaches 30°C or 15 minutes have elapsed.
The pump continues to operate even if the boiler shuts down.
1.14.5.3. Plate DHW anti-freeze function
On the KC model, the anti-freeze function also protects the DHW circuit.
When the DHW temperature sensor detects a temperature of 5°C, the boiler switches on and stays on at its minimum heat output until the
temperature reaches 10°C or 15 minutes have elapsed (the deviating valve is in the DHW position).
During the DHW anti-freeze operation the temperature detected by the flow probe is constantly checked, and in case it reaches 60°C the burner is
switched off. The burner is switched on again if the operation request in anti-freeze mode is still present and the flow temperature is below 60°C.
The pump continues to operate even if the boiler shuts down.
1.14.5.4. Water cylinder anti-freeze function
The water cylinder probe measures the temperature of water in the cylinder. When this temperature is less than 5°C a cylinder anti-freeze function
begins: the circulating pump begins working and the burner is switched on.
In KR and KRB models featuring an external water cylinder (optional) for the production of DHW with a NTC type temperature sensor (10 kΩ @
ß=3435; refer to water cylinder technical specifications) the anti-freeze function also protects the water cylinder.
When water cylinder temperature sensor detects a water temperature of 5°C, the boiler switches on and stays on at its minimum heating output
until the temperature of the cylinder water reaches 10°C or 15 minutes have elapsed. The pump continues to operate even if the boiler shuts down.
