Fernox leak sealer

[baby_belling]

hi what is the difference between Fernox leak sealer f4 express and superconcentrate version apart from the express type is cheaper in price. Can both be used for combi boilers and how effective are they at curing pressure drops. thanks

 

[transam]

Leak sealers can work I have used them with success , however ther is a risk in useing them , some heat excs don't like it , I have blocked the heat exc on a boiler useing it !!! so you take a chance that even if it does not work eg seal the leak , you might cause more problems for your self ?? doubt there is any difference in the 2 except one comes in a bottle were as the concentrated one is in a cartridge ???