Manufacturer

Model/Range

Pump Overrun

Fan Overrun

Frost Protection

Alpha

240E, 280E, 240XP

5 mins in ch mode

None

<5 degC boiler fires to 30 degC

Alpha

240P, 280P,

5 mins in ch mode

low speed at rest

<5 degC boiler fires to 30 degC

Alpha

240X

No

low speed at rest

none

Alpha

240XE, 240 Eco

5 mins in ch mode

low speed at rest

<5 degC boiler fires to 30 degC

Alpha

CB 25-33

3 mins

30 Secs

8o runs boiler to 30o on Primary Sensor 

Alpha

CB24,CB24X

30 secs,0 in HW only

20 seconds

Activated below 8 deg C Via PCB + CH sensor

Alpha

CB28, CB28X

30 secs,0 in HW only

20 seconds

Activated below 8 deg C Via PCB + CH sensor

Alpha

CD 18R 

Temperature & Time

Temperature & Time

8o runs boiler to 30o on Primary Sensor 

Ariston

Ariston Clas HE R

External Pump overrun - 3 minutes

external pump at 3-8 deg if 9 deg not achieved appliance fires -30C

Ariston

E Combi

internal pump at 3-8 deg diverter alternating for 20 mins if 9deg not achieved appliance fires -30C

Ariston

Eurocombi 23MFFI

via heating probe + pcb. 5degC boiler fires to 58 Deg C

Manufacturer

Model/Range

Pump Overrun

Fan Overrun

Frost Protection

Ariston

Genus 23 MFFI

via heating probe + pcb. 5degC boiler fires to 58 Deg C

Ariston

Genus 27 MFFI

via heating probe + pcb. 5degC boiler fires to 58 Deg C

Ariston

Genus 27BFFI

none

Ariston

Genus 30 MFFI

via heating probe + pcb. 5degC boiler fires to 58 Deg C

Ariston

Micro combi 23MFFI

Pump - After DHW demand 30 secs - After CH satisfied 3 minutes

Fires on min rate @ 3 DegC  and heats to 33 Deg C

Ariston

Micro Genus 23MFFI

Timed from PCB and controlled by jumper JP 5 (CMP I PCBs have no pump over run features

Fan over run after hot water demand 

Controlled by primary sensor  At 8degC pump runs and off at 15deg If temp drops to 3degC the boiler fires at min gas only until boiler temp is 33degC 

Ariston

Micro Genus 27MFFI

Timed from PCB and controlled by jumper JP 5 (CMP I PCBs have no pump over run features

Fan over run after hot water demand 

Controlled by primary sensor  At 8degC pump runs and off at 15deg If temp drops to 3degC the boiler fires at min gas only until boiler temp is 33degC 

Baxi

80e, 105e

30 secs 

< 5°C boiler fires till 30°C

Baxi

Bahama Honeywell

30 seconds

Baxi

Bahama Sit

10 seconds

No

<5°C boiler fires to 30°C

Baxi

Combi Instant 105e

30 seconds   

pre-heat facility

Manufacturer

Model/Range

Pump Overrun

Fan Overrun

Frost Protection

Baxi

Genesis 80, 96

3 mins after a ch demand

none

Baxi

Maxflow

<5°C boiler fires

Baxi

Solo 2 & PP3 Series

Approx 8 mins

Via pcb + sensor

Baxi

DUO TEC/Platinum

HW - 30sec, CH - 3min 

10 sec

<5°C boiler fires to 30°C

Biasi

Parva M90 24S,  28S

Fires @ 4 Deg C via PCB & ch thermistor            

Biasi

Prisma 24S, 24SE

none

Biasi

Prisma 28S, 28SE

none

Biasi

Riva Advance 47-970-29/30/31/32/33/34

Zero to 8.5 minutes

Via HW sensor, less than 4 degrees will fire the boiler around HW circuit until 60 degrees, boiler protection only

Boulter Buderus 

500-24S -24C

Preset to 5mins

Flow NTC @8o fires to 17o , less than 2o boiler locks out

British Gas

ICC1/Energy saver

<7 degC pump runs,<3 fires to 10 degC

Broag 

Avanta Plus Series 

Hw on Temp C/h 2-99 minutes 

less than 7 degrees pump only-- less than 3 degrees burner  via primary thermister 

Crosslee

Trisave FS 80/C

5-10 mins

Ferroli

 F 30 B & F 24 B

6 minutes set time 

If less than 5 minutes then fires until 14 degress 

Ferroli

76FF, 77FF, 100FF

6 mins in CH, 10 secsin HW

low speed at rest

Dedicated stat.  

Manufacturer

Model/Range

Pump Overrun

Fan Overrun

Frost Protection

Ferroli

Domina 80e

6 Mins  

Via primary sensors, fires the boiler at 7 Deg C to 14 Deg C

Ferroli

Domina 80N, 80N DGT & 80e

timed  (between 1 -20 mins)

if less than 5 degrees will fire boiler until 35deg then 6 mins pump o/run

Ferroli

Falcon 80

7-14 Deg C via Ch sensor

Ferroli

Hawk II

Dedicated stat

Ferroli

Maxima

Set @ 7 mins adjustable between 0-20 mins ……30secs on h/water

Less than 5 degrees will fire boiler until 15 degrees

Ferroli

Modena 80e,  102

6 mins

no

Via CH sensor + pcb 7degC boiler fires to 14 degC

Ferroli

Optima range

6 mins

Fires boiler + runs pump to maintain    4-12Deg C (dedicated stat)

Ferroli

Optimax

Set @ 7 mins adjustable between 0-20 mins ……30secs on h/water

Less than 5 degrees will fire boiler until 15 degrees

Gemini

960E

30 seconds

Glowworm

330

Timed for 5mins then reads from flow/return sensors if still above 60°C

Via flow sensor. 3°C burner fires until 10°C. Burner goes out pump runs on for 5 mins

Glowworm

Compact system 60ss, 100ss

< 10°C pump runs

Glowworm

CXI

3mins then checks temp if over 50°C pump continue suntil under 50°C, 20 secs overrun on hot water

Via flow sensor, 7°C pump runs, 3°C boiler firesuntil 10°C

Glowworm

Energysaver 100,100Mk2

Via flow sensor, <7°C pump runs,  <3°C boiler fires until 10°C

Glowworm

Energysaver 80,80Mk2

Via flow sensor, <7°C pump runs,  <3°C boiler fires until 10°C

Glowworm

HXI

Via flow sensor, 3°C burner fires until 10°C. Burner goes out pump runs on for 5 mins

Manufacturer

Model/Range

Pump Overrun

Fan Overrun

Frost Protection

Glowworm

ICC1/Energy saver

<7°C pump runs, <3°C fires to 10°C

Glowworm

Jaguar 23, 28

In ch mode only

<10°C pump runs, < 8°C boiler fires to 25°C

Glowworm

Micron (pump wired to chb)

Via PCB + Sensor  Pump runs @ 15°C

Glowworm

Micron(Pump wired to syst)

Via PCB + sensor when ext controls on and boiler stat off

Glowworm

SXI

Via flow sensor. 3°C burner fires until 10°C. Burner goes out pump runs on for 5 mins

Glowworm

Flexicom HX

5min

Yes - only a few sec

<8°C runs pump, if still not over 10°C after 30min burner will fire. <5°C burner fires.

Halstead

Ace

Inbuilt

Halstead

Dimplex

Timed @ 2 mins 

Post Purge

Below 5 Deg C  boiler fires on minimum until 20 Deg C

Halstead

Heat I 20-30-35

30secs

Boiler fires on minimum @ 6 degrees until 35 degrees on primary sensor

Halstead

Heat I 24-29 C

30secs

If over 78 degrees for 30 secs

Boiler fires on minimum @ 6 degrees until 35 degrees on primary sensor

Halstead

Quatro, gold, Wickes 2000

Dedicated stat

Dedicated stat. Lights <5degC

Hermann 

Eura HE 

?

?

Primary sensor below 5o runs boiler until above 10o 

Hermann 

Supamicra 24-30 HE

?

?

Primary sensor below 5o runs boiler until above 10o 

ICI Caldaie

Solar 80E, 96E

Via sensor + pcb. Fires burner if primary water drops below 5degC

ICI Caldaie

Solar twin

Via sensor + pcb. Fires burner if primary water drops below 5degC

Ideal

Icos

No   

No  

No  

Ideal

Icos System

5 mins  

No  

No  

Manufacturer

Model/Range

Pump Overrun

Fan Overrun

Frost Protection

Ideal

Isar

5 secs HW, 5 mins CH

No

pre-heat facility

Ideal

Logic Code Combi 26,33,38

Approx DHW 60 sec     CH 4 mins

DHW & CH 4 min

 <5degC fires boiler for short period via flow sensor and pcb

Ideal

Response SE

No

< 7 Deg C pump runs to 10 Deg C. < 3 Deg C boiler fires to 10 Deg C. Via flow sensor + PCB

Johnson & Starley

Reno

 2 minutes

Flow thermistor less than 5 degrees fires boiler until greater than 15 degree

keston

30C

DHW 75 sec     CH 4 mins

DHW & CH 4min

 <5degC fires boiler for short period via flow sensor and pcb

keston

C40,C40P,C55,C55P

2min timed off pcb

<7 degC pump runs,<3 fires to 10 degC

Main

Main HE41-474-01/02/03/04/05

Time = 2 minutes

Flow thermister lower than 5 degrees fires boiler until greater than 15 degrees

Myson

Midas Si

30 seconds

pre-heat facility

Potterton

Combi 80, Combi 100

Timed  between 1&3 mins

No 

Fires < 5 Deg C, heats boiler by 10 deg C approx

Potterton

Envoy

Timed on pcb 3 mins

Potterton

Lynx 2

Timed on PCB  

Potterton

Lynx RS

Dedicated stat

Potterton

Promax FSB 30 HE

None

Post purge 

Less than 5 degrees fires boiler until 15 degrees

Potterton

Puma 80, 100

Timed on pcb 4--9 mins 

<5 deg C boiler fires to give 10 deg C rise

Ravenheat

 CSI 120

3 minutes on heating, not HW

Less than 7 degrees pump starts, Less than 5 degrees will fire the boiler until temp raised above 7 degrees (boiler protection only )

Manufacturer

Model/Range

Pump Overrun

Fan Overrun

Frost Protection

Ravenheat

CSI 85 Range

3 Mins on c/h

Below 5 deg  will fire boiler until 7 deg

Ravenheat

LSF 100 Range 

3 Mins on c/h

Below 5 deg  will fire boiler until 7 deg

Ravenheat

RSF 82ET

3 Mins on c/h

Below 5 deg  will fire boiler until 7 deg

Saunier Duval

Ecosy 24E, 28E

3 mins on CH, 30 secs on HW

< 3 Deg C boiler fire to 10 Deg C 

Saunier Duval

Isofast F28E/1,  F35E/1

<6 degC boiler fires to 16 degC  *

Saunier Duval

Protherm 100 EC

< 10 Deg C pump runs, < 8 Deg C boiler fires to 25 Deg C

Saunier Duval

Protherm 80E   

< 10 Deg C pump runs, < 8 Deg C boiler fires to 25 Deg C

Sime

Format Combi 30HE

On temperature 

6o fires boiler until 15o (boiler only)

Sime

Format System 25HE 

On temperature 

6o fires boiler until 15o (boiler only)

Sime

Friendly Format Series

Dedicated stat

Sime

Murelle HE

pump overun 30 seconds after both demands

Adjustable in parameter 23  -5  to  5 degrees factory set at 3    pump and boiler

Vaillant

eco TEC plus 612, 615, 618, 624 & 630 (System Boilers)

Vaillant

eco TEC pro 28, plus 824 & 831 (Combi Boilers)

Yes 

<5°C boiler fires unltill flow temp 30°C

Vaillant

Ecomax 286

20-80 secs HW 20s-5min CH

5 secs

Inbuilt 

Manufacturer

Model/Range

Pump Overrun

Fan Overrun

Frost Protection

Vaillant

Ecomax/2E range  

Yes

< 8°C pump runs, < 5°C boiler fires via PCB + flow thermistor

Vaillant

VCW 242 E  *

ch mode only 5 mins hybrid, 20 secs non

20 Secs(both modes)

No

Viessmann 

Vitodends 100 WB1A

Yes

Yes   

Below 5o fires until above 15o

Viessmann 

Vitodends 200 WB2A

Yes

Yes   

Below 5o fires until above 15o

Vokera

Compact Combi

<7 Degc pump runs. If temp continues to drop then burner fires to 30 Deg C 

Vokera

Linea range

Above 80 Deg C°

Above 80 Deg C

at 7degC pump runs until 10 DegC. At 3 degC boiler fires to 30 degC

Vokera

Linear 25-30-35 HE

Yes (See Instructions)

Yes (See Instructions)

Primary Thermister (see instructions)

Vokera

Maxin 24E, 28E

Dedicated stat

Vokera

ProCombi A

Yes - Min 20sec but can be longer depending on boiler temp.

Yes - 10sec post purge if burner lit when demand ends

<6degC boiler fires on min until 35degC, checked by primary flow thermistor

Vokera

Compact HE 25/29

Yes - Min 20sec but can be longer depending on boiler temp.

Yes

<6degC boiler fires on min until 35degC, checked by primary flow thermistor

Worcester / Bosch

230 RSF

Temperature related

no

none

Worcester / Bosch

240 Combi BF

Dedicated stat

No fan

none

Worcester / Bosch

240 RSF

Dedicated stat, >60 Deg C

No

none

Worcester / Bosch

24CDi

4 minutes on C/h then Via CH sensor runs above 80 degrees

15 Seconds unless heat demand has NOT occurred within 30 mins then funs until drops to 80 Deg C 

<8 DegC Pump runs 4 Mins then monitors temp.  <5 deC boiler fires 30DegC

Manufacturer

Model/Range

Pump Overrun

Fan Overrun

Frost Protection

Worcester / Bosch

24i

Via CH sensor runs 60-70DegC

4 mins

< 6 DegC pump runs to 8 DegC, <4 deg C boiler fires to 20 Deg C

Worcester / Bosch

24si 2, 28si 2

Upto 4 mins on c/htg or fan overrun only depending on temp at primary sensor. No pump overrun on H.Wtr

15 seconds

Worcester / Bosch

280 RSF

Pump over-run only if primary water sensor temperature above 70deg C. 

No

Controlled by primary sensor. Pump runs for 4minutes if temperature less than 8deg C, if below 5deg C boiler fires until temperature reaches 30deg C 

Worcester / Bosch

28CDi

5 minutes on C/h then Via CH sensor runs above 80 degrees

15 Seconds unless heat demand has NOT occurred within 30 mins then funs until drops to 80 Deg C 

<8 DegC Pump runs 4 Mins then monitors temp.  <5 deC boiler fires 30DegC

Worcester / Bosch

Both versions of 350

None

>75C  to 65C

none

Worcester / Bosch

Cdi range, Ci range, Si range & C1 ICC1 etc

Temperature related   

Temp related

via primary sensor. 8degC pump runs for 4 mins every 30 mins. @  4degC burner fires to 20degC

Worcester / Bosch

Greenstar (all models incl ICC2 etc)

Timed on PCB

via primary sensor. 8degC pump runs. 4degC burner fires to 20degC

Worcester / Bosch

Greenstar Cdi 

3 mins   

30secs (adjustable )

If below  8°C pump runs untill flow reaches 12°C, if below 5°C boiler fires until 30°C  

Worcester / Bosch

Highflow 400

2 versions, dedicated stat or 

Worcester / Bosch

Highflow 400

Timed on pcb