Ideal Combi explosive noise


I have an Ideal Icos Combi boiler and few days ago I realized that it started to produce very loud, “explosion” like noise each time I open a tap with hot water. It is scary, but boiler is working- it still provides hot water. Can someone advice if it is sth serious and how it should be fixed?



Hi George

This is a pretty common fault on Icos boilers. An “explosive” noise is being produced because there is a lot of gas released by the ignition leads. Gas valve and speed fan adjustments will need to be done, in some cases flame sensors need to be replaced. You can find info how to do it troubleshooting section of this page, but if after reading you feel somehow uncomfortable with doing it yourself, call for the specialist.


Ideal Combi leaking?


I came from work, no heating, no hot water, went downstairs to check what is wrong with the boiler and I can see a puddle under it. Any idea what is wrong and how to fix it?

Best Regards


Hi Ryan,

Most probably heat exchanger is broken. You will need to call for service guy and get it replaced, unfortunately this is not a DIY task. How old is boiler? Have you thought of replacing it? Replacing heat exchanger will cost you a few hundreds and you don’t have a guarantee that next month sth won’t break again… I would consider replacing.

Ideal Elan Range not working


I have an Ideal Elan Range boiler and I just realized that there is no hot water and no central heating… I went down to check on the boiler and restart- I did it several times in the past and it helped. This time I realized that it is not working at all, I don’t see flame… and that happens for the first time. Should I re-light it myself or I need to call a service guy?

Best Regards


Hi Will,

If you have no experience working on gas boilers yourself, and you had some issues with the boiler before call a service guys straight away, mostly because you have no idea what caused a complete shut down this time. Guy will come, do all the checks, fire it and fix if needed. If everything is fine, it won’t cost most than an hour job.

Ideal Elan very noisy

Hi All,

I have an Ideal Elan gas boiler and it is stored in the bathroom. I never had any problems with it, but in last days it is so loud I can hear it in the bedroom. The sound is almost like kettle boiling- hope you know what I mean. I am pretty sure it is not normal. What’s wrong? It is still under warranty and I could give it back, but maybe it is sth that can be fixed easily… Anybody an idea?



Hi Robert,

Usually two things cause noise issues: first is the lack of water in the system (you need to re- pressurize till over 1.5 bar) or the header tank is empty (refill it) or frozen (replace because it got damaged). First two you could try doing yourself for the third you need a specialist, and if frozen then I am afraid that warranty won’t cover it.



Ideal Combi luke water

Hi Folks

I have an Ideal Isar Combi boiler, it’s no longer  under warranty and I use it for both hot water and central heating. Central heating is currently switched off, I switched it off about a week ago, and that is when my problems with the hot water started. Currently boiler provides hot water for only 5-10 seconds and then the water goes luke or even cold. Any idea what may be the issue?



Hi Dave

Could you check what is the pressure in your system? If the pressure is under 1 bar and from your description I assume it is, you will need to simply re-pressurize the system till around 1.5 bar and it will solve your problem. I would try doing it myself, and only if no luck, I would call a specialist to come and help

Ideal Isar HE30 no central heating


I have an Ideal Isar boiler model HE30, it is being used for hot water and central heating. We bought and installed it around 5 years ago, it is serviced every year, I should probably add that boiler is located in the storage room. During the whole period we never experienced any problems with it, today we woke up in the morning and it is very cold in the house, we have 3 month old baby and service guy doesn’t pick up the phone. Can someone help? Hot water is working normally. What should we do?

Best Regards


Hi Tom,

First restart your boiler and check your radiators after approximately 20-30 min. If that won’t help check if no one set your thermostat to different setting- check and set it to the highest position, wait for another 20-30 min to see it boiler picked up the message and central heating started to work. Go to the room where boiler is located and check if you hear that the boiler is working (no hot water should be used while you are checking). If yes, but radiators are still cold you will need to get a local Gas Safe Registered guy (any guy- doesn’t have to be your service guy) to come and replace the thermostat.


Ideal Isar HE24 L:F flashing

Hi Guys

I have an Ideal Isar boiler model HE24 and it is pretty old, but so far was working just fine. Today morning I realized there is neither heating nor hot water at home. Boiler displays L:F message. What does it mean? How to fix it fast? What is better (cost) fixing issue yourself or calling customer service?


Hi Josh

Looks like overheating fault. If I were you I would start with resetting the boiler- to to this press D button and wait for couple of seconds, boiler should restart. If it restarts and everything works fine- your problem is solved and it is definitely cheapest solution. If not call Gas Safe Engineer from your area, overheating components shouldn’t be replaced by anyone without proper qualifications.