When servicing a room-sealed gas boiler, it is crucial to follow the proper regulations to ensure both safety and compliance. The following guide is based on the key UK regulations that apply to room-sealed gas boiler servicing:

• Gas Safety (Installation and Use) Regulations 1998 (GSIUR): This legislation mandates that only Gas Safe-registered engineers may service or maintain gas appliances. It also requires room-sealed appliances to be serviced as per the manufacturer's instructions.
• Building Regulations Part J: These regulations cover the safe installation and operation of combustion appliances, including ventilation and flue requirements.
• BS 5440-1: This British Standard provides safety requirements for flueing and ventilation in room-sealed appliances.
• BS 7671 (IET Wiring Regulations): Ensures electrical safety, particularly around live metal components near or within the boiler system.
• Manufacturer’s Instructions: Always adhere to the servicing instructions provided by the boiler's manufacturer.

By following these regulations, you can ensure that the servicing procedure is both compliant and safe.

1. Request Manual, boiler make, location, and how many bedrooms are in the property.
2. Ask the reason for the boiler service: is it just annual or is there a problem?

1. Request manual and any history. Notes: It is important that the Manufactures Instructions (MI's) are available and if possible, the service booklet. It is also essential to follow BS7593:2019 Part L of the building regulations and MI's guidelines.More...
2. If reinstating gas, follow the gas reinstating procedure.
3. Bring all service tools, protective covering and lay out as appropriate.
3. Prepare analyser with address details and service book, so that the writing work can be started in the service booklet, save having to do this later and make sure that analyser is sharing the date with the phone if possible.

1. Inspect flue, room size, flame, combustion air, cooker flame and condensate pipe. Inspect the flue for any leaks, blockages, or signs of corrosion along its entire length, ensuring compliance with BS 5440 standards. Verify the flue is properly positioned relative to windows and doors to ensure safe ventilation.More...
2. Check the boiler starts in both hot and cold water modes.
3. Perform a safe-to-touch test with the voltage pen (against a live plug socket or switch spur, check the case, piping and flue, also checking the gas meter, then check the pen is still working.)More...
4. If the boiler is not room sealed... Perform a spillage test by closing all windows, doors, and adjustable vents in the room. Run the boiler at its maximum heat input for at least 5 minutes, ensuring no combustion products are leaking back into the room.More...

Your Notes

1. Let By Test: 7-10mb for 1 minute (0.25 acceptable). (If fails, check ECV then for passing, then contact 0800111999.) More...
2. Stabilization Test: 20-21mb for 1 minute, then test for 2 minutes. (On older appliance, refer to pages 6.6 table 6.5!!!) More...
3. Slowly turn gas 'ON' and purge if gas pressure is below 7mlbs. Notes: When purging installation volumn less than or equal to 0.02 m3 in a well ventilated area, the vent gases can be release into the atmospear either through an appliance burner such as the cooker or by opening a union closest to the appliance such as the boiler until you can smell gas in accordance to the 'Domestic Gas Safety On Site Guide Part 1, chapter 6, part 6.5' referencing: 'Purging Installations'. Taking note that purging above 7mlbs is also required if air has been let into the gas pipe. More...
4. Record standing pressure. Notes: should be 18.5 to 30mlbs, concerns above 28mlbs. More...
Enter Standing Pressure:
5. Check operating pressure by turning on the hot water tap. Example: 21mlbs +/- 2mlbs(19 to 23 mbrs). Always consult the appliance manual to confirm the manufacturer’s recommended operating pressure and document the findings accurately. More...
Enter Operating Pressure:

Your Notes

Boiler servicing MUST comply with the current building regulations. Since the 15th June 2022, all new homes must produce 31% less CO2 emissions than what is currently acceptable in the pressent Part L building regulations. Last updated on the 2nd Febraury 2023 - Quoted here on the 24th October 2024.More...

1. Turn power and gas off to the boiler, unplug or take fuse out, and lock up.
2. Isolate water to the boiler, including the flow and return on the central heating. In the event the flow and return will not turn off, just drain down regardless from the boiler and continue.More...
3. Take boiler cover off and place screws in to the magnetic dish. Noting: Make sure the seals to the boiler case if any are checked making sure they are not damaged in any way.More...
4. Check for any leaks, wear and tear and take notes.
5. Remove and clean the heating exchanger with 50% water and 50% vinegar. Noting: This method of cleaning is best with a spray bottle, a scrubbing brush and a jug of water, also a thin instrument to get imbetween the elements of the coil. Rinsing away the debris is very important.More...
6. Clean the probes within the heat exchanger. Noting: When cleaning the probes, this is best being done with a file and not wire wool.More...
6. Remove and clean the condensate trap.
7. Drain the boiler and pressurize the expansion vessel to between 0.8 and 1 bar using pump. Also... Before putting the dust cap back on, check with LDF, for any passing air. This may be best using a bent syringe if it is too awkward to get liquid in the airvent.More...
8. Close the drain point on the boiler and reopen central heating isolation valves, bleed the system and pressurize, then let air out inside the boiler and pressurize again if required.
9. Turn boiler back on and test by running hot tap. You may at this point check around the boiler using the gas analyser rather than just waiting to set the gas analyser up later on as instructed below subject to 'Set Up Testo 300 Flue Gas Analyser part 9 using the CO Ampbient test for ppm.'More...

Your Notes

1. Run the hot tap for 2 minutes and measure the gas rate. Example: Reading 1 0.115 Then Reading 2 0.201 x 30 = 2.58m3/hr or 24.9kw (Easier to use an app) More...
Reading 1: Start 2-Minute Timer 2:00
Reading 2: Measurement Duration (minutes):
Calculate Gas Rate

Gas Rate: m³/hr, Gross kW: , Net kW:

2. Check cold water temperature and litres per minute. Notes: Subject to the size of the gas boiler in kW, the temperature could go to 60°C; however, the ideal temperature in the home, according to research, is 50°C.More...
Cold Water Temperature (°C): Observed Hot Water Temperature (°C): Flow Rate (L/min):
Calculate Actual Boiler Output

Actual Boiler Output: kW

3. Check inlet gas valve standing pressure using a digital gauge.
Inlet Standing Pressure:
4. Perform gas rate test on central heating for 2 minutes. Example: Reading 1 0.233 Then Reading 2 0.368 x 30 = 1.05m3/hr or 10.1kw (Easier to use an app) More...
Central Heating Reading 1: Start 2-Minute Timer 2:00
Central Heating Reading 2: Measurement Duration (minutes):
Calculate Gas Rate

Gas Rate: m³/hr, Gross kW: , Net kW:

5. Any defects found during the servicing process should be reported to the responsible person... (e.g., the homeowner or landlord), either through an advisory notice or a formal warning notice. More...

Your Notes

1. Turn on the gas analyser, and click customer’s details. Notes: Could use as default or could add name and email address.More...
2. Measuring site subject to non default details: A Name of measuring site: (Example: Apartment 1 or 1 The Close. BL8 3QD B All other info is optional, then save the measuring site and click select. Now selected data is assigned to this customer. C Click Flame gas in top left, then click ‘Flame Gas’ and click play to let it take in natural air (20.6 to 20.9).More...
3. Place analyser probe in flue 150mm.
4. Turn the boiler ‘ON’ and in ‘TEST MODE’. This can be done by clicking the resset button and choosing 'Low' for a minimum of 15-minutes to 30 minutes and take gas readings.More...
5. Take low operating pressure. Example: 23mb. (Minimum on MI’s could say 17.5)More...
6. Take high operating pressure. Example: 20mbMore...
7. The combination of CO and CO’2 should come under 0.0004 or... as per the manufacturer’s instructions, adhering to relevant standards such as BS 5440. CO2 should not exceed the manufacturer's recommended levels.More...
8. Perform natural air reading (20.6 to 20.9%).
9. Do an integrity sweep test around the heat exchanger. Notes: The correct procedures for this using the Testo T300 is to click the burner mode, clear the probe using oxygen (O2) and then choose 'CO Ambient', which should show 'AmbCO ppm'. Some people check the heat exchanger by running their hand around the heating exchanger or use a mirror to check any steam, however, care MUST be taken at your own discretion. This should enable you to find out if you have heating blowing out.More...
10. Take Testo T510! out, tighten screw and LDF.
11. Put case back on, and do integrity sweep test for 2 minutes Notes: making sure the results are below 10PPM.More...
12. Turn 'Test Mode' off.
13. Final check before checkign the water quality is to check the safety device on the boiler is working.Notes: To do this, you would turn the hot tap 'ON' and then turn the gas valve off and listen out for a click and the boiler bringing up the fault code that generally refers to 'No Gas', then turn the gas valve back on and run the hot tap to get it working again.More...

Your Notes

1. Inspect and clean the filter.
2. Take tap water and central heating sample Notes: A taking a central heating sample of water, check with stability tube that the water is clear enough. B Check PH on kitchen tap, and Cwater on central heating by filling sample cups up using the i-Test by Scalemaster.More...
3. Take out test strip and sand.
4. Open i-Test app and put in address.
4. Place probe into sender unit Notes: let it connect and press start on the app whilst placing the sender unit with probe into the tap water.More...
5. After about 30 or 60 seconds, place in heating water for 4 minutes and place inhibitor if required.

Your Notes

1. Complete all necessary documentation.
2. Ensure all safety and servicing logs are updated.
3. Service is now complete!

Your Notes

1. Check notes to see why the blanking disc has been fitted. Notes: If the boiler has been isolated for precautionary reasons, such as requiring a service, you can proceed with reinstating the gas.More...
2. Perform the safe-to-touch test under 'Visual Check Following Regulation 26.9 (3)'. Notes: If disconnecting the meter union, ensure you use the earthing safety cable to bond any live metal components, both upstream (before the meter) and downstream (after the meter), to avoid static discharge.More...
3. If only a service is required and there is no downstream damage from the Emergency Control Valve (ECV), remove the blanking disc and reseal the meter connection.
4. Follow the 'Gas Meter Safety Checks' steps 1 to 5. However, the gas pipe will need purging. Notes: To purge the gas pipe, open the gas connector furthest from the appliance and purge until you can smell gas. Use LDF (Leak Detection Fluid) on all joints. If the furthest point is the cooker, it may be favorable to purge via the cooker if it’s the most distant point and near the boiler.More...
5. After purging and completing the necessary checks, you can begin the 'Boiler Service'.

Your Notes