How to use leak sealer

sunnyday1234

Hi
I have a sealed oil fired heating system and we are in the house 4 years and i dont think it has ever been really right. A few years ago i had lots of air locks and pressure would drop to zero in a few days, i would refill and it would be fine again for a few days but then the rads would get half cold and be full of air. Then all of a sudden the issue stopped happening and even though the pressure was low the rads were fine. 
Last week it started happening again and now the pressure drops from 1 bar to zero overnight so i think i have a leak. I have a plumber near me and he said to start with a leak sealer and hope for the best :-)
Does anyone know how i put this into the system ? Whats the easiest way of putting it in without risking water going everywhere. 

As it takes 1-2 days i presume its a small leak or weep as opposed to be a big one (hopefully)

We bought this house after it was unfinished and left idle for about 5 years and some of those years were over the bad winter so its possible there are leaks, hopefully small ones. Has anyone had good results with the leak sealer ? 

Thanks for any help

complicit

If your pressure is going down that quickly, leak sealer is not the answer. You should make sure the expansion valve and pressure release valve in the boiler are not faulty, if they checkout OK then you need to locate and repair the leak(s)

sunnyday1234

complicit wrote: »

If your pressure is going down that quickly, leak sealer is not the answer. You should make sure the expansion valve and  pressure release valve in the boiler are not faulty, if they checkout OK then you need to locate and repair the leak(s)

Ok thanks, i want to do this right and get the issue sorted once and for all. How and where can i check the expansion valve and pressure release valve ? 
I see a few guys online in Munster that specialise in leak detection, am i better getting one of these specialised guys in instead of a local plumber ?
Is it worth checking all the rads for weeping etc ?
I presume a specialist in this would be better than a local plumber
http://www.findaleak.ie/index.php/leak-detection-cork

complicit

I would get a heating engineer in first, leak detection specialist would come later

sunnyday1234

complicit wrote: »

I would get a heating engineer in first, leak detection specialist would come later

ok thanks, a heating engineer as in a plumber ? Or are these different :-), sorry for my ignorence

Can a plumber service the boiler ?

K.Flyer

sunnyday1234 wrote: »

ok thanks, a heating engineer as in a plumber ? Or are these different :-), sorry for my ignorence

Can a plumber service the boiler ?

A plumber can, if they have the correct equipment, training, experience and knowledge to do it correctly.
Contact https://www.oftec.org for more information.