Common Problems

I never seem to have enough hot water. We only get enough for one bath a night?

a. It may well be the fact that your old gravity hot water system is causing these problems. The best way to resolve this is by having the boiler replaced and the system upgraded to fully pumped, this gives you the head faster and assists in a faster recovery time for your water.

I’ve never bought central heating before. I’m not sure who best to choose?

a. Best advise is to consult your dealer / installer. Your dealer will help you to choose the right capacity boiler and gather up ancillaries required for boiler room for an optimum system for your needs.

My boiler makes such a noise when it fires up?

a. More commonly referred to as kettling, this is due to sludge / scale deposits that accumulate in the heat exchanger over the years. Your system may benefit from a chemical flush but it doesn’t always guarantee to get rid of the noise. The only way to completely get rid of it is to change your boiler and ensure your installer chemically flushes your new boiler and system.

Our spare bedroom at the back of the house is always cold?

a. This could be due to a few different factors, poor circulation caused by sludge or a weekend central heating pump. The radiator itself may be undersized or the system may just need balancing. It would be worth your while getting a system engineer out to have a look at what is causing the exact problem.

Some rooms get too hot. I can’t seem to be able to control that?

a. You would benefit from having trvs fitted (thermostatic radiator valves). They independently control each radiator giving you more or less heat wherever you wanted it, cool bedrooms, hot hallways and bathrooms, comfortable lounge. They also have the added benefit of saving you Money on your gas bills as the central heating system is not always on full fire.

The radiators never seem to warm up enough, they may be warm at the bottom but are cold at the top?

a. This is usually an indication that air has got into the system somewhere and has become trapped. Air in a radiator will rise to the top forming a pocket stopping the hot water from getting to that part. This can be released, but remember to turn the heating off first. Now, armed with a rag beneath, use a radiator key to slacken the air bleed valve which is at one end towards the top of the radiator. There will be a hissing sound as the air comes out. As soon as water begins to flow, close the vent again and wipe away any water. Take care not to get scalded – the water may be pretty hot. The heating can then be switched back on.

The radiators are cold at bottom and hot at the top?

a. This is a sign of rust and sludge build up which is sitting in the bottom of the radiator. Following the guides on removing and refitting a radiator, take the radiator outside and flush it through with a hosepipe. If you have the radiator standing on end, you should be able to flush out most of the sludge. Remember to carry the radiator upside down so you don’t get sludge dripping on to your carpet.
With an open vent system, you may also consider using a proprietary heating system sludge remover. This will mean adding it to the feed and expansion tank and, a few days later, emptying and refilling the system. Follow the manufacturer’s instructions.

The shower in the bathroom is useless, it’s like a dribble?

a. If you have an old combination boiler installed, they have very poor flow rates. New modern boilers have a more improved flow rate which will improve the flow from your shower. Always check with your installer for the compatibility of your new boiler to your existing shower.


Insulation is Important:

An uninsulated loft allows a huge amount of heat from your home to be lost, unnecessarily increasing your fuel bills. Even if you already have some insulation, check to see that it is adequate. The current thickness recommendation is 150mm.To insulate the area is a relatively cheap and easy job to do.
General Solid Fuel Operational Problems


  • Frequent accumulation of fuel wastes in system
  • Slag formation

Reason: Bad and poor quality fuels.
Causes: Boiler capacity and efficiency loss.
Solution: Ask your fuel supplier for quality fuels and always be sure to use quality fuels.


  • Difficult combustion,
  • Smoke, over pollution.

Reason: Dirty Fuels.
Causes: efficiency and boiler capacity decrease due to insufficient air flow thru system.
Solution: Ask your fuel supplier for quality fuels and always be sure to use quality fuels.


  • Fire go outs
  • Uneasy combustion

Reason: Excess Moist content in Fuel.
Causes: Moisture decreases combustion chamber temperature which leads to capacity and efficiency decrease as most of the heat generated consumed by water during gasificiation.
Solution: ask your fuel dealer for dry, quality fuels. Air-dry for a season if wood is being used and air-dry coals (not directly under sun light) for a season.


  • Condensation in chamber and in chimney. (Water flows when ash door is opened)
  • Accumulation on the walls of chamber which is very difficult to clean.

Reason: Low operating set-temperatures
Causes: Condensation causes volatile ashes sticks to chamber walls and Eventualy causes corrosion and decreases of product life time. Also Fuels in core state cools down rapidly due to condensation and forms tar on grates or on walls.
Solution: Do not set operating temperatures below 65°C (or 149°F)


  • Soot in walls and tubes.
  • Heavy black smoke trough chimney

Reason: Adding fresh Fuel on top of burning fuels
Causes: Newly added fuels release volatile flammable gases rapidly, and with insufficient air to burn them all, leaves the system through chimney unburned. Efficiency is lost.
Solution: Do not add fresh fuel on burning fuels. Only add fresh fuels when previous fuels burned down to core state.


  • Uneasy burn
  • Backfires when boiler door is opened soot in walls and tubes.

Reason: Insufficient Flue Drag
Causes: Insufficient flue drag prevents boiler to work 100% capacity. Causes backfires and poisonous gases if there is a leak in the system. Excess accumulation of soot and tar in chamber and tubes are a sign of this problem.
Solution: Check your chimney diameter is correctly set up by an installer. Also see if there is any obstacles in it and see if drag is unobscured.


  • Fuel consumption is high

Reason: Excess Flue Drag
Causes: Excess flue drag causes boiler to work over 100%. Excess air in system decreases flue gas temperatures and causes efficiency losses.
Solution: Check your chimney diameter is correctly set up by an installer. If not change it to fit the system.


  • Ignition problems
  • Fuel consumption is high
  • House is not warmed up

Reason: cleaning / maintenance period of the boiler is required.
Causes: The layer formed on the chamber surfaces blocks heat transfer operation and decreases efficiency. The layers formed in tubes increases resistance and causes difficulties in ignition and combustion.
Solution: Regularly have your boiler cleaned and maintained by mechanic.