vokera 80xl sp losing pressure slightly

[unclefewst]

HI, a little bit of advice please, i have in the last six months or so, been replacing the radiators in my daughters house that she aquired as a mortgage repossession, the house having stood empty for some 15 months or so, and the heating having never been used, it became necessary to change the radiators and pipework configeration, that is all done now and everything fine, the system works well the house is warm, rads hot and hot water, there was a need to change the diaghram in the diverter as it was all sludged up, this was done by a heating engineer, he had trouble getting the pump running all black gunk and sludge, but he did and it worked ok, i then drained down, replaced rads, and left for some considerable time checking foor leaks underfloor boards (which there were non ) before replacing boards, i added the inhibitor and cleaner and boiler noise chemicals that are available to cleanse the system, it now runs fine, however the boiler tends to loose pressure and needs to be pressed up, but not very often, i dont believe there to be any problems on the side where i have done the remedial pipe work, but suspect the boiler due to it being all manked up with sludge and stuff prior to the engineer getting it running again, any suggestions would be appreciated, i am thinking about prv's ev's and the like or anything else within the boiler,

ps, i am sure to this time, (and it is a few months now) that any leak would have shown itself through the ceiling boards etc, but the place is dry, and radiator tails are dry etc

 

[twgas]

You may have a very small leak in the boiler, on a rad valve or a fitting etc. I didn't see how often you repressurise the system (occassionally doesn't really help).
Has the system been cleaned properly - reading you post it looks like you added all the correct chemicals, but altogether and just left them!

 

[unclefewst]

i suppose i need to pressure it up about once a month, if that, it was all drained down, flushed through several times then chemicals added, should be nice and clean now, as i say all works champion, but cause for concern on the need to keep pressuring up about once a month, and then only a bit dave

 

[kevplumb]

could be a slight weep on a rad valve gland as above

it will dry up before you notice it

 

[twgas]

i suppose i need to pressure it up about once a month,

That could be very hard to find - depends on several factors, ie how much pressure you actually lose in relation to system size.

it was all drained down, flushed through several times then chemicals added, should be nice and clean now,

This is not the right way, if the chemicals have been in the system for the correct length of time, as per the MI of the cleanser, the system will need flushing through each lowest point until it runs clear, then refilling with inhibitor, and I would suggest fitting a Magnaclean or similar, also adding an internal leak sealer might help with the pressure loss - but I wouldn't guarentee it.

 

[unclefewst]

You may have a very small leak in the boiler, on a rad valve or a fitting etc. I didn't see how often you repressurise the system (occassionally doesn't really help).
Has the system been cleaned properly - reading you post it looks like you added all the correct chemicals, but altogether and just left them!

yep thanks for that, it was all flushed through a few times and then inhibiotr and cleanser entered, i say its only very occassionaly that it needs pressing up, once a month to bring it up to 1 bar, but apart from that it works fines nice and hot and hot water, i think i will check all the radiator glands as the other chap mentioned first, then explore the prv aspect etc, dont really want to be taking up carpets etc, as i am not wholly convinced there is a problem sub first floor
dave

 

[twgas]

it was all flushed through a few times and then inhibiotr and cleanser entered

What I'm trying to tell you is cleanser is not usually added with inhibitor, it's put in before, THEN flushed out (as per MI), only when system is clean is inhibitor added and left in.

 

[unclefewst]

it was all flushed through a few times and then inhibiotr and cleanser entered

What I'm trying to tell you is cleanser is not usually added with inhibitor, it's put in before, THEN flushed out (as per MI), only when system is clean is inhibitor added and left in.

sorry mate, i didnt make that very clear did i, it was all flushed through , and then i added the inhibitor and boiler noise reducer, they can be left in together, they are a well known brand, from plumbase something one and something 2, they are not strictly a cleanser
my mistake dave

 

[twgas]

...that didn't take long then.