new boiler fitted/losing pressure help

[bwatt]

Need some help i had a boiler that was approx 18yrs old maybe older and it finally needed replaced,i think it was the expansion vessel that was gone on it,i was losing water from it when it was switched off,so near everyday i needed to top it up,and the water was escaping outside.

Now i ordered a new boiler vokera from mr central heating and had a local plumber install it,he did a good job and all looked ok but since he has done the job i would say its been topped up with water 3 times or was it 4 cant remember.
One time it was just showing on the red and thought it best to top up and anyway if its on the red does it do harm,pther time it was not working and needed reset so it much have went lower and next time it was same as first.

Now my plumber said when i asked him how much times i needed to top with water he said about every 3/6 months,well i have topped it up within about 4 week about three times which is not right.
I looked at the boiler and i cant see any leaks coming from it so he did his job right?But he said if i am having to top it up like this in such short time then there must be a leak somewhere.
I checked my radiators and there is nothing so i am puzzled,he then said it maybe under my floor boards.
Problem is where could be anywhere,there is a shop below me and i asked if any water coming through roof they could not see anything.
Its a minor leak but i have no idea where its leaking it thats the problem.

I should not have to top up a new boiler this much and i am not happy now the boiler is 12 months warranty,could it be the new boiler?could it be something the plumber did?Or is it a leak and if so where as i can find anything.
I purchased the boiler from mr centralheating and the plumber had nothing to do with it apart from installing it,would i have to pay him again to see what the problem is or should i be covered by the cost i paid him first time round as its still not right.
There may have been a leak when i had my old boiler in some of my pipes under floor baords but i cant tell and its too big of a job to rip up every board in house to check as heating all over house.

I asked if there was stuff as i heard you can put stuff into system that seals the pipes from leaks but he told me that its not good to use this with the new boiler it does not do the boiler any favours.

I am puzzled as to what to do,im not sure if its a problem with my boiler the plumbers work or somewhere in my house where i have checked every radiator.

Please give some advise.

 

[Softus]

Its a minor leak but i have no idea where its leaking it thats the problem.

There may have been a leak when i had my old boiler in some of my pipes under floor baords but i cant tell and its too big of a job to rip up every board in house to check as heating all over house.

I am puzzled as to what to do,im not sure if its a problem with my boiler the plumbers work or somewhere in my house where i have checked every radiator.

Unfortunately this isn't always an easy one to solve. You might already know, but the possible causes of loss of pressure are:

1. Leaking rad valve - can be small and the water could be evaporating before it drips anywhere.
If you turn off the system and wrap a piece of tissue around each rad valve, then you would be able to spot a leaking rad valve.

2. Radiator corrosion in progress, generating gas in rads.
Did your installer use a chemical inhibitor?

3. PRV opening - check the drain tube outside the house.
(Common causes of this are faulty expansion vessel or faulty PRV.)

4. Leaking pipework - eek!

 

[Slugbabydotcom]

Theres not a lot anyone can say without seeing the job which is why your post has been up for six hours without reply.
Check the pressure relief pipe, which I suspect has already been done also the automatic air vent.... A likely culprit. There will be tell tale marks around it if that is the problem. The water could come out a drip at a time and instantly evaporate in the heat.
After that it depends whether you would rather work or pay money to solve the problem. Options
1 Work ... Rip up floorboards etc.
2 Money .... Use some Leak Sealer

I cant see the leak sealer causing any problems but my view of it is [excuse the naff simile] that its like using a sticking plaster on a wound that may need a bandage or even an amputation and prosthesis.