Boiler Loosing pressure everyday and leak

10 Feb 2022
Reaction score
United Kingdom
Hello All

I would really appreciate your help if someone can. I have Main Elite ECO 30 Combi boiler. It looses pressure everyday and every morning I have to top up the system a little bit in order to clear low pressure alarm E119.

I noticed a small leak on the left corner on a plastic thing at the back, not sure what it is but looks like you can tight it a little bit. You can see it in the picture and water marks on the switch below.

Can anybody suggest what it is and how to stop this leak please ?

Thanks a lot in advance



  • WhatsApp Image 2022-02-10 at 18.50.17.jpeg
    WhatsApp Image 2022-02-10 at 18.50.17.jpeg
    158.8 KB · Views: 91
  • Capture.PNG
    1.2 MB · Views: 96
Sponsored Links
It's the condensate trap ,you should get a gas engineer to investigate and repair.
Looking at the chrome plated FCU and the corrosion on it , it would appear to have been leaking onto it for some time. Probably got more than one issue.
Sponsored Links
Thanks "terryplumb". Spoke to an engineer and he cant come and see before Monday so kind of want to see if i can do it myself. Does it not come off from the bottom if I unscrew it ?
Thanks Ianmcd and terryplumb, I don't see any leakage anywhere else, Just want to know if this trap can be removed if I unscrew it ? it is a small leak but enough to raise the E119 alarm and yes i think its been happening since last few months since i extended my property and moved this boiler.
You shouldn’t be removing the condensate trap as it forms part of the flue.
Check on top of boiler,can’t remember if there’s a aav there.
Put your pressure up. Then Turn the boiler isolating valves off outer right and left ones leave for a day using hot water as normal and see if pressure drops if it does the leak is on the boiler.
Second pic those pipes are covered in water drips what had you attempted before taking pic

DIYnot Local

Staff member

If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.

Select the supplier or trade you require, enter your location to begin your search.

Are you a trade or supplier? You can create your listing free at DIYnot Local

Sponsored Links