ProTech Boilers

Boiler FAQs

Your Boiler Questions Answered By Professionals

Before undergoing any major work on your home central heating system, always make sure that you fully understand the positives and negatives. Take a read of our FAQs below to learn more about new boiler installations, repairs and servicing. Feel free to contact us for more information.

General Boiler FAQs

Using a system boiler is an extremely economical and efficient option for heating your home. For many people it can be difficult to tell the difference between a system boiler and regular boiler. What is the most important difference? System Boilers take up far less space to be installed than the regular boilers. This is because they incorporate the cistern tank as well as all other major components, but also still provides a constant flow of hot water. A system boiler is ideal for larger premises with not enough space for storage purposes.

All the system boilers already have the majority of vital components of a functional heating system built in. This makes installation quicker and easier. The hot water is being pumped through the radiators as well as the hot water cylinder when you use a system boiler. This brings a faster response, and as a consequence your heating becomes more economical and has lower running costs. Since all of the major components are built into the single casing, the space requirements are much lower, and the installation is much easier.

Pros:

  • Lower space requirements as all the most important components are built in.
  • Extremely economical, easy to install, and fit in limited spaces.
  • Faster hot water response on demand.

Cons:

  • Loses heat if the cylinder is not insulated properly.
  • Insufficient cylinder insulation results in waiting for the boiler to heat up again if you wish to take a hot bath.
  • The size of the tank dictates the quantity of hot water at your disposal.

Pros:

  • Ideal for older buildings
  • Perfect in scenarios where a lot of hot water is being spent (large buildings and buildings with multiple occupants)
  • Ideal for homes that have more than one bathroom
  • Ideal for areas where water pressure is low.
  • Can be combined with various solar water heating system

Cons:

  • They require huge spaces
  • They are not energy efficient, especially in the cases where the tanks have poor insulation.
  • The amount of hot water at your disposal is defined by the size of the tank.
  • The main components (heating system and the water pump) are separated, thus require more space.

Pros:

  • Compact design is ideal for smaller places where the space is limited
  • Combi boilers are an ideal option when there is no loft
  • Decreased home pipework
  • Perfect for freshly built premises
  • Energy efficiency increase

Cons:

  • The main water pressure needs to be sufficient
  • Can’t run multiple hot taps at the same time
  • Water pressure in the shower is directly dictated by the main water pressure
  • In cases of breakdowns, there is no alternate source of hot water

Replacing a boiler that has been worn-out will definitely impact your account balance. Still, there are positive impacts of replacing it and upgrading your heating system. This is especially obvious if you don’t have the room thermostat system or you don’t use TRVs.

The estimates from the relevant sources say that the heating system participates with no less than 60% of the total energy consumption of your household! It is easy to fathom that the more energy efficient boilers can contribute to significant savings in this department. The majority of the new boilers that has been “A” rated have up to 90% energy efficiency or even more! Your old boiler can fall in many energy efficiency groups, but the majority of them are labelled as the “G” devices, which means that their energy efficiency stands somewhere between 55% and 70%. This comes as a consequence of using a non-condensing technology. Your annual saves on gas bills can be as high as £200-300, Depending on your gas consumption.

If you are turning your boiler on just two times a day, if you do not use the hot water in them, it is a pure waste of energy. The water in the tank will cool down if left there for too long, even if the insulation is good, and the energy used will be used irreversibly. In these cases, a combi boiler is a perfect solution. It will provide all the hot water you need, ONLY when you need it, so the losses generated by the redundant heating will become non-existing!

 

  • Is your boiler more than 15 years old?
  • Is the energy efficiency rating of your boiler below ‘A’?
  • Does it take a while for your boiler to heat up?
  • Does your boiler need frequent repairs?
  • Is the cost of maintaining your boiler on the up?
  • Are you heating a large hot water tank regardless if it gets used or not?
  • Does your boiler make strange noises?
  • Are your fuel bills on the up?

If you find yourself answering yes to any of these questions, it may be time to replace your old boiler.

Boiler Fault Codes

Fault CodePossible Fault
9AIncorrect HCM fitted
9UProblem with the code plug (faulty or not connected)
B7Replace control board
C6Running too fast / Running too slow
C7Fan not running / Fan not running or airflow blocked
D1Sensor wet or damaged (the boiler will block for 300 seconds before this condition)
D1Sensor disconnected or damaged (the boiler will block for 300 seconds before this condition)
D1Boiler overheat
E2Flow sensor shorted or damaged
E2Flow sensor disconnected or damaged
E5Primary flow sensor overheated
E9The main heat exchanger has overheated.
Maximum temperature 105°C
E9Maximum temperature sensor on the main heat exchanger has failed
E9Maximum temperature sensor on the main heat exchanger has not been recognised
E9Flue gas thermostat overheat
EAFailure of four ignition attempts. The boiler waits 30 seconds before another attempt is made
EAAn established flame has been extinguished.
This could be caused by:
moisture in the sump, due to a blocked sump/condensate trap.
a strong wind into the flue
EAGas valve coil disconnected
EAFlame not established during the first 4 seconds ignition period
EAThere is an error where the pump is not detecting water – check pressure gauge and repressurise to 1 bar.
Fault CodePossible Fault
H.01 – .00Temporary Fault – Temporary loss of communication between gas valve and boiler board. Fault in air/gas unit.
Loose connection to gas valve.
H.01 – .05Temporary Fault – Maximum difference between the flow and return temperature exceeded. Non-existent or insufficient circulation. Sensor error.
H.01 – .08Temporary Fault – Flow temperature increasing too fast in heating mode. Non-existent or insufficient circulation.
Sensor error.
H.01 – .14Temporary Fault – Maximum flow temperature value exceeded. Non-existent or insufficient circulation. Non-existent or insufficient circulation.
H.01 – .18Temporary Fault – No circulation of water. Non-existent or insufficient circulation. Sensor error.
H.01 – .21 Temporary Fault – Flow temperature increasing too fast in DHW mode. Non-existent or insufficient circulation. Sensor error.
H.02 – .02Temporary Fault – No input of parameters C1/C2. PCB not configured.
H.02 – .03Temporary Fault- Incorrect configuration settings C1/C2.
H.02 – .04Temporary Fault – Parameter error. Incorrect parameters.
H.02 – .06Temporary Fault – System water pressure. Water leak on boiler. Water leak on system.
H.03 -.00Temporary Fault – Communication error with NTC flue sensor. Sensor not, or badly connected. Bad connection. Sensor fault.
H.03 – .01Temporary Fault – Communication error with the HMI PCB. HMI not connected.
H.03 – .02Temporary Fault – No flame during operation. No ionization current.
E.00 – .04Permanent Fault –  Return temperature sensor open-circuit. Sensor not or badly connected. Bad connection. Sensor fault.
E.00 – .05Permanent Fault – Return temperature sensor short-circuit. Sensor not or badly connected. Bad connection. Sensor fault.
E.01 – .02Permanent Fault – Temperature measured by return sensor greater than flow sensor. Bad connection. Sensor fault. Sensor not or badly connected.
E.01 – .04Permanent Fault – Loss of flame detected 5 times in 24 hours (With burner on). No ionization current.
E.01 – .11Permanent Fault Requiring Reset – Incorrect fan speed. External draught over the boiler. Defective gas/air unit.
E.01 – .12Permanent Fault Requiring Reset – Temperature measured by return sensor greater than flow temperature.
E.01 – .17Permanent Fault Requiring Reset – No circulation. Sensor not or badly connected. Sensor fault.
E.01 – .20Permanent Fault  – Maximum flue gas temperature value reached (>140 Deg C). No circulation. Sensor fault.
E.02 – .00Permanent Fault  – Boiler reset in progress. Reset button has been pressed.
E.02 – .07No or low system water pressure. Low system pressure (less than 0.5bar) boiler will not function.
E.02 – .16Permanent Fault –  On board CSU time-out. Check PCB for damage.
E.02 – .17Permanent Fault – Permanent loss of communication between gas valve and boiler PCB. Fault in air/gas unit. Loose connection to gas valve.
E.02 – .19Permanent Fault – Jumper 1 changed. Check position of jumper 1.
E.02 – .20Permanent Fault – Jumper 2 changed. Check position of jumper 2.
E.02 – .21Permanent Fault – Jumper 3 changed. Check position of jumper 3.
E.02 – .47Permanent Fault – Connection to external device unsuccessful. Check wiring to external device.
E.02 – .48Permanent Fault – Configuration to external device unsuccessful. Check pairing to external.
E.04 – .00Permanent Fault  – Gas valve fault. Gas valve not detected.
E.04 – .01Permanent Fault  – Flow temperature sensor short-circuited. Sensor not or badly connected. Bad connection. Sensor fault.
E.04 – .02Permanent Fault  – Flow temperature sensor open-circuited. Sensor not or badly connected. Bad connection. Sensor fault.
E.04 – .03Permanent Fault – Critical flow temperature reached. Non-existent or insufficient circulation.
E.04 – .04Permanent Fault  – Flue temperature sensor short-circuited. Sensor not or badly connected. Bad connection. Sensor fault.
E.04 – .05Permanent Fault – Flue temperature sensor open-circuited. Sensor not or badly connected. Bad connection. Sensor fault.
E.04 – .06Permanent Fault – Critical flue gas temperature value reached. No circulation. Sensor fault.
E.04 – .08Permanent Fault – Maximum safe temperature value reached. (Safety thermostat open-circuited). No circulation. Sensor not or badly connected. Bad connection. Sensor fault.
E.04 – .10Failure to light (could be gas supply issue).
E.04 – .12Permanent Fault – False flame signal. Short-term fluctuation of the mains. Ionization current present even though there is no flame. The burner remains very hot (CO2 too high). Defective gas/air unit.
E.04 – .13Permanent Fault – Fan rotor blocked. Fan seized. Wiring to fan damaged.
E.04 – .17Permanent Fault – Problem with gas valve. Defective gas/air unit.
Ideal Status Codes
Display CodeSystem Behaviour
0The boiler is in standby mode awaiting either a central heating call or hot water demand
CThe boiler has a call for central heating but the appliance has reached the desired temperature set on the boiler
DThe boiler has a call for hot water but the appliance has reached the desired temperature set on the boiler
CThe boiler is operating in central heating mode
dThe boiler is operating in hot water mode
FThe boiler is operating in frost mode
  
Ideal Fault Codes
Fault CodeSystem Behaviour
C0BCC Activation Fault
C2BCC Fault
F1Low Water Pressure
F2Flame Loss
F3Fan Fault
F4Flow Thermistor
F5Return Thermistor
F6Outside Sensor Failure
F7Low Mains Voltage
F9Unconfigured PCB
L1Flow Temperature Overheat or No Water Flow
L2Flame Loss
L55 Boiler Resets in 15 minutes
L6False Flame Lockout
CodeMeaningCause
F.49eBUS faultShort circuit on the eBUS, eBUS overload or two power supplies with different polarities on the eBUS
F.52Mass flow sensor connection faultMass flow sensor not connected/disconnected, plug not connected or incorrectly connected
F.53Mass flow sensor faultMass flow sensor faulty, filter below venturi filter cap wet or blocked, gas flow pressure too low
F.54Gas pressure fault (in combination with F.28/F.29)No or too little gas supply pressure, gas valve closed
F.56Fault: Mass flow sensor regulationGas valve defective, cable harness to gas valve defective
F.57Fault during comfort safety modeIgnition electrode highly corroded
F.61Fault: Gas valve regulation
  • Short circuit/short to earth in cable harness for the gas valve
  • Gas valve defective (coils shorted to earth)
  • Electronic defective
F.62Fault: Gas valve switch-off delay
  • Delayed shutdown of gas valve
  • Delayed extinguishing of flame signal
  • Gas valve leaking Electronics defective
F.63EEPROM errorElectronics defective
F.64Electronics/NTC faultSupply or return NTC short circuited, electronics defective
F.65Electronic temperature faultElectronics overheating due to external influences, electronics defective
F.67Electronics/flame faultImplausible flame signal, electronics defective
F.68Unstable flame signal faultAir in gas, gas flow pressure too low, wrong air ratio, condensate route blocked, wrong gas restrictor, ionisation flow interruption (cables, electrodes), flue gas recirculation, condensate route
F.70Invalid device specific number (DSN)Spare part case: Display and PCB replaced at same time and DSN not set, wrong or missing output range coding resistor
F.71Flow NTC faultFlow temperature sensor signalling constant value:
  • Flow temperature sensor incorrectly positioned at supply pipe
  • Flow temperature sensor defective
F.72Flow/return NTC faultFlow/return NTC temperature difference too great → flow and/or return temperature sensor defective
F.73Water pressure sensor signal in the wrong range (too low)Interruption/short circuit of water pressure sensor, interruption/short circuit to GND in supply line to water pressure sensor or water pressure sensor defective
F.74Water pressure sensor signal outside correct range (too low)Cable to water pressure sensor has short-circuitedd at 5V/24 V or internal fault in water pressure sensor
F.75Fault, no pressure change detection when starting pumpWater pressure sensor and/or pump defective, air in heating installation, too low water pressure in boiler; check adjustable bypass, connect external expansion vessel to return
F.76Overheating protection on primary heat exchanger has respondedCable or cable connections for safety fuse in primary heat exchanger or primary heat exchanger defective
F.77Flue non-return flap/condensate pump faultNo response from flue non-return flap or condensate pump defective
F.78Interruption to DHW outlet sensor at external controllerUK link box is connected, but hot water NTC not bridged
F.83Flow and/or return temperature sensor temperature change fault
  • When the burner starts, the temperature change registered at flow and/or return temperature sensor is non-existant or too small.
  • Not enough water in the boiler
  • Flow and/or return temperature sensor not in correct position at pipe
F.84Fault: Flow/return temperature sensor difference implausibleFlow and return temperature sensors return implausible values
  • Flow and return temperature sensors have been inverted
  • Flow and return temperature sensors have not been correctly fitted
F.85Fault: Flow and return temperature sensors incorrectly fittedFlow and/or return temperature sensors have been fitted to the same pipe/wrong pipe
F.92Coding resistor faultThe coding resistor on the PCB does not match the entered gas family. Check the resistor, repeat the gas family check and enter the correct gas family.
F.93Gas group faultCombustion quality outside the permitted range: Wrong gas restrictor, recirculation, wrong gas family, internal pressure measuring point in venturi blocked (do not use lubricant on O-ring in venturi.). Gas family check prematurely terminated.
Communication faultNo communication with PCB

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ProTech Boilers

Unit 31 Louis Pearlman Centre,
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HU3 4DL

01482 352643