Monthly Archives: May 2014

Repairing your gas boiler

Gas Boiler Repairs

There are any number of things that can go wrong with a gas boiler. Here we identify some of them and, where possible, offer solutions.

With all issues involving gas boilers, if you are in any doubt contact a registered gas engineer. A gas-fired hot water boiler has many parts, valves and controls, but for the most part they are fairly reliable and when they do have problems, these usually relate to the expansion tank or water circulator pump(s).

Three common problems with gas boilers

Problem 1 – Boiler produces no heat

Possible causes include: no power; a low water level; a malfunction with the pilot light or electronic burner ignition; or a thermostat malfunction.

Possible repairs:

  • If the circuit breaker or fuse controlling the furnace is tripped or blown reset the tripped circuit breaker and/or replace the blown fuse. The boiler’s automatic filling system using the pressure relief valve should maintain proper water level by maintaining a 12-15 psi pressure. If you do not have a pressure reducing valve you can also manually feed the boiler by oping up the water feed valve until boiler pressure reaches 12 psi.
  • Relight pilot light.
  • Move thermostat setting for temperature up and down a few degrees.

Problem 2 – Poor heating performance

A sudden change in performance might be due to incorrect water levels, a more gradual change might be related to mineral deposits in the boiler and heat exchanger.

Possible repairs:

Check the combination pressure / temperature gage, and if the water pressure is low (below 12 psi) the system needs to have water added. The boiler’s automatic filling system using the pressure relief valve should maintain proper water level by maintaining a 12-15 psi.

If you feel the problem might be mineral deposits in the boiler, flush the system or call a service technician to do this task.

Problem 3 – Expansion tank has excessive water and inadequate air

There are two basic types of hot water boiler expansion tanks. There is the older style large horizontal steel tank and the newer style smaller diaphragm tank. In older boiler systems the steel expansion tank may be found in the attic or suspended between joists in the basement. In newer systems the diaphragm expansion tank may be attached to the boiler piping near the boiler. The expansion tank must be properly charged with air to prevent water in the system from boiling and exceeding the desired 12 psi of pressure.

Some of the signs that you have a problem with your expansion tank include: water spurting from the pressure relief valve on the boiler; an abnormally high pressure reading on the gauge (above 20 psi), and the tank is hot to the touch from bottom to top.

Any of these symptons suggest that there is too little air and too much water in the expansion tank.

Possible repairs:

If the bottom of the tank doesn’t feel hotter than the top it must be bled or drained of excess water. To do this, turn off the boiler, close the water shut-off valve and let the tank and system cool. The expansion tank combination valve will release water and let in air. Attach a hose to the combination valve and drain about three gallons of water. If there is no combination valve on an older tank, then shut off the valve between tank and boiler and totally drain expansion tank. Open the water supply valves and let the system fill back up. Turn the boiler back on and let it recharge. Let the system run for 1-2 hours and then recheck it.

By recognising problems and knowing how to deal with some of the common issues, you can save a lot of money on call-out charges.

Installing a combi boiler

So there you are, you have done all the research and checked all your options and you have bought your new combi boiler. Purchasing a new combi boiler is the easy part – once you have established which type is best suited for your needs and budget, then the new boiler can be with you in just a few days. But how to install it?

Which boiler?

The first decision to make is whether to choose the all-in-one purchase directly from the manufacturer or do you opt for a fitter separate from the retailer? The former will save time and effort, the latter may save you money and you have control over the selection of the engineer/installer. And what about if you want to install the combi boiler yourself. For some people this will sound like a nightmare scenario, but many people relish the challenge, the learning process, the sense of achievement that comes from completing this intricate piece of DIY work.

Making the right choice

Installing a combi boiler is not a simple task. In fact, it is a legal requirement that if you are installing a gas combi boiler, you MUST hire a Gas Safe engineer to do the work. Installing any combi boiler involves a lot more skill, time, technical knowledge and DIY confidence than many other home improvement tasks. Typically, installing a combi boiler will take a couple of full days’ work and there will be a lot of equipment lying around the house while you are doing the work. Be aware that you will be without heating while the work is being done, so ensure you are prepared and your family is aware of the implications of your endeavors.

Preparing for upheaval

Before you even begin, you may need to rip out the older storage-tank heating system, which can lead to dust, upheaval and old boiler parts all over the house. Suitably warned, you’re more or less ready to get started.

How To Install a Combi Boiler:

  • Know the law: There are a number of laws and regulations regarding combi boiler installation, including the Part P of the UK Building Regulations. These outline the best ways to avoid risks such as fire or physical injury and also reference more specific areas of concern such as how to handle electrical wiring.
  • Read your instructions manual: Read over the instruction manual thoroughly, making sure you know exactly what needs doing and in what order. It’s also a good idea to lay out and list all the materials before you begin too; count out the unit, flue, all the necessary copper-piping and new radiators.
  • Plan, plan, plan: Before installation, figure out where all your materials need to be placed; that includes a place for the boiler unit (which contains the hot water storage cylinder, pump, feed/expansion tanks and controls all in one); positioning your new radiators for optimum heat exposure and ensuring each item is surrounded by enough space for air circulation and follow-up maintenance.
  • Follow directions: If your project includes installing new radiators, you will need to map out your pipe routes. A colour-coded tape system could be useful here to define which pipe goes where. Your pipe routes will usually involve a two-pipe (parallel) system, which includes an initial flow-line and a secondary return pipe.
  • At the business end: Now for the real task, fitting your boiler to the wall and setting up all the necessary pipe work. Before you start, switch off all electrics and water. This task will obviously take the longest, and you cannot afford to rush it or cut corners. Everything must be exactly where it should be and is properly fitted and secured.
  • Bleeding radiators: If you have new radiators you will need to bleed them before they become operational. Bleeding involves turning the valve or key at the bottom of each radiator until a small amount of water spills over the top, catch this with a cloth.

With all home improvements, paying enough care and attention will mean that you are able to do a great job at a fraction of the cost of calling out the manufacturers to do the job for you. And then there is that great feeling of satisfaction with a job well done.

Installing a gas boiler

Gas boiler installation

When it comes to installing a gas boiler, you must ensure the person carrying out the installation is qualified and competent and is working in compliance with the Gas Safety and Use Regulations.

Steps to success

The first stage of installation is to unpack the boiler and parts and check each piece carefully to make sure it is all working correctly. As well as the boiler parts there should also be an installation manual, a warranty card. Also in the pack. there should be a mounting bracket, fixings, valve and boiler template.

Stage 1 – Using the boiler template, mark on the wall the positioning of the boiler, it is important that you follow all the spacing recommendations outlined in the installation manual.

Stage 2 – Drill the holes for the mountings and plug them, then fit the boiler mounting plate. The boiler can then be positioned on the mountings. At this point secure the boiler, using the bottom fixing points.

Stage 3 – You are now ready to start connecting your boiler. At this point care must be taken to ensure that you follow the instructions in the installation manual to the letter. The gas isolation valve is marked differently to the other valves and has a different shaped washer to distinguish it from the others. Ensure all the valves are secured.

Stage 4 – These are the standard boiler connections, check each one is connected, and then double check the connections: flow, return, PRV, gas, condensate, hot water outlet, cold water supply.

Stage 5 – The boiler has an inbuilt magnetic filter, which helps protect the boiler’s internal components and a filling loop, which should be connected between the cold main and the return pipe work.

Next steps…

The next stage of the process is fitting the flue and power. The flue must protrude 140mms from the outside wall to the end of the terminal. It is connected to the boiler by an internal adapter. These must be lined up carefully. Finally connect the flue bend to the flue connections on the boiler, there is a rubber seal and a metal band to connect these correctly.

The next stage is to connect the boiler to the external power source. Remove the electrical connection cover, route the cables through the grommets and connect according to the instructions in the manual. The power cables must be connected to a three amp spark. Once all the connections have been completed, replace the connection cover.

Energising the boiler

You are now ready to energise the boiler. Normal operating pressure is 1.5 bar but at this stage pressurise it to 2 bar. The boiler will show an error message of E02, indicating low pressure – simply press the reset button to see the actual pressure.

Bleed all radiators and open automatic air vent. Before starting the system take a moment to re-check everything and make sure it is all installed as per current industry regulations and standards. Purging and gas soundness tests should also be carried out at this stage. All boilers are preset to factory settings and should not need resetting. At this point the boiler pressure should be running at 17 milibars. Check CO2 readings at the flue and make sure that all readings conform to the installation instructions manual.

Your boiler should now be installed and working perfectly.

Boiler repairs – know your system

Boiler repair

To repair a boiler there are two fundamental types of information you need to understand about your boiler. The first is what your boiler consists of – the components that make up a boiler; the second is the sequence of activity that leads to your boiler working efficiently.

If you understand the components and their tasks, and can identify what action leads to the boiler working efficiently, then you will be far better informed and will be able to make decisions about repairing the boiler when things go wrong.

Dealing with problems

While many malfunctions require professional help, there are some issues that can be dealt with by someone with a fundamental knowledge of how a boiler works. The simplest to understand is a combination boiler or combi.

This is a fairly simple system that works to provide central heating and hot water. What many people don’t know is that a combi boiler only does one thing at a time. It either heats water or provides central heating. A valve, known as a diverter valve will decide which way to send the water, either to the central heating or to provide hot water.

Getting to know your system

Inside the combi boiler there are a number of different components, and it is worth having a look at the manufacturer’s instruction manual to familiarise yourself with how your boiler works and the components within the system. This makes it easier to diagnose problems if they occur – and with a little knowledge, you may be able to identify the problems and make the repairs yourself.

What is the correct sequence of events for a working combi boiler?

It all begins with an action – the central heating is switched on or a tap is turned. This prompts the fan within the boiler unit to kick into action and blow air. In turn this activates the air pressure switch, which then activates the gas valve. These are the three fundamental stages of boiler activity.

A closer look at how things work

The gas valve opens and gas goes into the main heat exchanger. This will then light up (ignite) a flame and via the flame rectification device, the PCB will send out a message to keep the gas going. If the PCB does not send this message then the gas will switch off immediately – this is an inbuilt safety device. Once the flame is lit and the system is working, the water in the boiler heats up.

As it gets hotter the water will turn to steam and expand. The expansion vessel takes up the expansion of the water. If an expansion vessel fails, then another safety device is in place – this is a pressure release valve, which pushes excess water out of the expansion vessel safely.

At it’s simplest, this is how a boiler works. To fully understand what the process involves, take a few minutes to study the manual and identify the process. And if you are in any doubt, contact a professional boiler technician.

10. Common Problems with Boilers

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By: MoToMo

“Our central heating system is like hygiene – as long as it is okay we don’t notice it, but the minute there is a problem it becomes a real issue.” explains David White, a plumber in Epsom. No matter how well ordered our lives, a broken boiler and the accompanying lack of heating and hot water can plunge us into chaos, and quite often, misery.

A winter of misery

While a broken boiler in the summer can be a real inconvenience, the majority of boiler breakdowns will occur at the start of the winter. For a few months the boilers have been inactive, and then when the weather turns colder, they are forced back into life and this is when expensive and inconvenient problems can arise. And of course, that is the time when everyone is experiencing problems so it could be a few days before an engineer can even get to see you.

Some common boiler problems can be solved without the need to call in a heating engineer, while others will require the services of a qualified and experienced professional. If in doubt, it’s always best to seek professional help from a reputable central heating engineer. At least, using our guide, you will be able to identify many of the issues and then decide upon the best, and least expensive, course of action.

Here are the 10 most common problems you are likely to encounter:

  1. No heat or hot water – potential causes include broken diaphragms and airlocks, failure of motorised valves, issues with the thermostat or low water levels.
  2. Leaking and dripping – a variety of issues could cause your boiler to leak water. It will depend on where the water is leaking from to determine the cause.
  3. Strange banging, whistling or gurgling noises – air in the system is a common cause, alternatively it could be that the water pressure is too low or it’s kettling.
  4. Pilot light goes out – could be a broken thermocouple which is removing the gas supply to the pilot light, a draught blowing the pilot light out or a deposit built up in the pilot light.
  5. Losing pressure – a water leak in the system is the most common reason for a loss of pressure. But it could also mean that the pressure relief valve needs replacing.
  6. Frozen condensate pipe – Thawing a frozen condensate pipe should ideally be done by a qualified engineer.
  7. Thermostat issues – if the thermostat is losing accuracy or turning the heating on/off when its not supposed to it might be time to invest in a newer, more energy efficient one.
  8. Kettling – hearing a strange rumbling noise? When lime scale builds up on your boiler’s heat exchange the water flow is restricted. This water starts to heat and steam and the noise you get is referred to as kettling.
  9. Radiators not getting hot – corroded pipework can cause sludge to gather in the system, preventing the free flow of hot water to the radiators. Chemically cleaning or flushing the system will remove these deposits.
  10. Boiler keeps switching itself off – could be low water pressure, a problem with the thermostat or a lack of water flow due to a closed valve, air or the pump not circulating the water in the system properly.

Boilers and their repair – FAQs

FAQs

What is the cost of a new boiler?

Boiler prices range from £500 for a basic gas model up to £2,200 for a large external oil boiler. But remember, you’ll also need to pay for installation.

How reliable are boilers?

According to a 2012 Which survey, it was found that two thirds of people who’d bought a boiler since April 2005 have experienced some kind of fault, which meant their boiler didn’t heat their hot water or radiators. Not all of these faults needed repairing, but 32% of boiler owners have had a visit from a boiler repairer.

How can I find a reliable gas boiler engineer?

Quite often you can go on recommendations from friends or colleagues, but whoever you choose to service your boiler, make sure he or she is on the Gas Safe Register. This is the official gas registration body for the United Kingdom, Isle of Man and Guernsey, appointed by the relevant Health and Safety Authority for each area.

By law all gas engineers must be on the Gas Safe Register. Gas Safe Register replaced CORGI as the gas registration body in Great Britain and Isle of Man on 1 April 2009 and Northern Ireland and Guernsey on 1 April 2010.

What is the cost of installing a new boiler?

It really depends upon what type of boiler you are going to choose, but these prices cover your basic requirements:

New boiler: £500-£1,500 depending on make and model

Heating engineer labour: £500-£1,000

Optional requirements:

Adding a magnetic filtration system: £120

Powerflushing 10 radiators: £300

Adding new radiators: £70-£150 per radiator depending on size & position

New wireless programmer and thermostat: £180

Adding Thermostatic Radiator Valves (TRVs): £20 per radiator

New hot water cylinder  (120 litre): £250-£300

New hot water cylinder  (250 litre solar compatible): £800-£1,000 depending on current installation

Upgrade gas supply pipe from meter to boiler to larger diameter pipe: £120-200

Install condensate drain pipe: £150-£250

Condensate pump, if access to a drain from the boiler is difficult: £100

How can I prevent my boiler’s condensate pipe from freezing?

To prevent freezing, boilers retain condensate water and then let it out in a gush. However, particularly cold weather can still cause the water in the condensate pipe to freeze. This is especially true if the condensate pipe is external. If your condensate pipe is frozen, your boiler will probably switch itself off – exactly the opposite of what you need in freezing weather.

To get your boiler going again, try the following steps: Use warm, but not boiling, water to unfreeze the pipe’s contents. This is only a temporary fix if the weather remains cold.  Lag the pipe with insulating material. If the pipe is at a shallow angle or very narrow, it may need to be reinstalled. The larger and more vertical the pipe is, the better.