Mamiya C28, C32, C24 manual From

FINDING

FAULT FINDING

Continued from

page 53

FAULT

	no	Is there max burner
Is there a temperature rise
of 35 ûC across the DHW		pressure* when the
circuit at:		boiler first lights?
10.0 L/min 24 kW model
11.7 L/min 28 kW model
13.1 L/min 32 kW model		yes
yes

Is the maximum water

flow correct

10.0 L/min 24 kW model

12.0 L/min 28 kW model

14.0 L/min 32 kW model

	no	Is there between 0V dc and
With the DHW hot
		16V dc at the connections
does the burner
		on the modulating coil?
pressure modulate if
		(0=min, 16=max)
the DHW temperature
setting is reduced to		yes
minimum?
		Is the burner pressure within
yes
		min and max value* with
		the boiler running?
		yes
		Replace faulty gas
		valve.

no						no
	Is there > 17 mbar						Rectify gas supply
	gas pressure at the							fault.
	gas inlet?
		yes
	Adjust the max setting
	on the gas valve. Refer
	to frame 35. Check that
	max burner pressure*
	can be achieved.
no						no
	Is the cold water supply						Rectify water supply
	adequate? refer to frame							fault.
	6 and Table 1 at page 4.
	yes
	Check the DHW inlet
	filter. Remove debris
	and clean or replace
		filter.
no							no
				Is the continuity of the				Repair or replace
			modulator harness O.K?					faulty wiring.
no					yes
	Adjust burner pressure.
	Refer to frame 35.
				Replace faulty PCB

Boiler Operating

Correctly

* see Table 2 at page 4 for the correct value

58 mini HE --- Installation & Servicing