1.5 to 0 bar in less than 24 hours

Gary Busey

Well, I have just replaced 6 water pump valves on my mothers sealed central heating system. All were leaking slowly due to fibre washers. (i replaced them due to the corrosion rather than replace with rubber washers)

Anyway, I drained the upstairs and the attic as needed and did the swap. I then refilled the system while venting rads untill I got up to 1 bar. Revented and refilled till all air was removed.

I then turned heating on and balanced the 22 rads in 3 zones:rolleyes: Everything is working 100% but I went back yesterday to check the pressure and it dropped to .2bar. I then refilled and bleed each rad again in case air was in the system(no air, water straight away) Turned on and everything again 100%.

I again went over today and same story, I hadto refill from .2bar.

I no you may have to refill a few times as the small bleeder valve in the HP allows air out but is this normal? Did I forget something here

Additional info. Boiler is 1 year old, baxi megaflow 32. Sealed system. 4 pumps on system. 1 for each zone and 1 in the boiler. 3 2 port valves for 3 zones and what looks like 2 filling loops side by side in the attic above the HP.
The origional filling loop wont fill the system above .8 bar but the new one fills it fast directly into the 2 added rads in the attic.

Anyway, anyone know whats goin on here? will this fix after a few more refills?? System never needed a refill since new boiler was added.

Any other info needed, let me know and I can try to clarify it better.........Thanks in advance:)

gdavis

are motorised valves in manual when filling? ie. when u are refilling,could a zone be off and not filling?have u checked that safety valve is not passing?is old filler loop tank fed? new one,mains? neither should be left connected to system,non return may be faulty.coil in cylinder leaking?

Gary Busey

gdavis wrote: »

are motorised valves in manual when filling? ie. when u are refilling,could a zone be off and not filling?have u checked that safety valve is not passing?is old filler loop tank fed? new one,mains? neither should be left connected to system,non return may be faulty.coil in cylinder leaking?

Hi, cheers for reply. Had valves on man when emptying and during refill yes. Safety valve not passing?? is this the relief valve? I checked the overflows to make sure no water was passing but didnt see any so ok. I opened both loops to fill. Not sure why theres 2(maybe to fill two attic rads) Although when i open the old one it takes about 5 minutes to refill but the new one does it in around 40 seconds, strange as they are 5 inches away from eachother on the mains line. I know they should be disconnected but they are right inside a storage area where someone can stand on the easily turnable valve and flood the place. In saying that i will change them to screw slotted valves for safety and disconnect. As for non return. I dissconected both hoses briefly to see was there backflow. I will put a blank on them tomorrow when i change the gate valves. This should eliminate most of the problems. As for leaking coil, I would say its ok as problem is only since the refill although im not sure how to test it anyway.

Em not sure whats next but a few inexpensive possibilities I can try tomorrow. Cheers

Gary Busey

Is there a possibility the pressure gauge is connected to an auto fill valve after the loop. In do I need to leave filling loop on? Not sure if I turned this off before drain down. There was two but cant remember if one was left on or not. Oh and system went from 2 bar to 0 in 6 hours last night so im doing something wrong

Gary Busey

refilled again from .8 to 1.5 bar. Auto air vent bottle thing in hot press seems to be lightly hissing no stop since the refill?

So it is dropping .5 bar in about 2 hours. Could this be just excess air vent from pipes? No water coming from overflow to tank so that rules out leaking coil.

My head is melted, please someone give me a solution before i do something stupid:o

Gary Busey

Just put a bag around the overflow to boiler. water is coming out from there. id say about 30mm in 5 minutes so I think this is the problem. Boiler is baxi megaflow 32 he ie. Any remodies? and why this only after refill?

.jacksparrow.

Gary Busey wrote: »

Just put a bag around the overflow to boiler. water is coming out from there. id say about 30mm in 5 minutes so I think this is the problem. Boiler is baxi megaflow 32 he ie. Any remodies? and why this only after refill?

Generally once the safety value starts leaking its near impossible to get them to seal again.replacing may be the best option.

Actually you said overflow to boiler,are you mixing this up with safety valve?

Gary Busey

.jacksparrow. wrote: »

Generally once the safety value starts leaking its near impossible to get them to seal again.replacing may be the best option.

Actually you said overflow to boiler,are you mixing this up with safety valve?

not sure. when the heating goes on, water gradually comes out the 18mm wavin pipe into the drain outside.

.jacksparrow.

Gary Busey wrote: »

.jacksparrow. wrote: »

Generally once the safety value starts leaking its near impossible to get them to seal again.replacing may be the best option.

Actually you said overflow to boiler,are you mixing this up with safety valve?

not sure. when the heating goes on, water gradually comes out the 18mm wavin pipe into the drain outside.

Ah that sounds like the condense trap,its normal for that to happen on a condensing boiler.

gdavis

is there another pipe going out through wall,half inch copper/qualplex? and is that dripping.?can u put up pic of 2 filler loops?

Gary Busey

The copper pipe doesnt seem to be dripping but the small wavin filled a glass in a hour so im gonna replace PRV tomorrow and go from there. If thats not the culprit il bridge the flow and return to the cylinder to bypass the coil and test that. Il let you no how it goes and take some pics tomorrow. Cheers for replys

Oh and what is the copper pipe for? and what is the wavin pipe for?

gdavis

wavin is condensate.its supposed to drip

Gary Busey

gdavis wrote: »

wavin is condensate.its supposed to drip

spanner in the works so. if its lost 500ml of water surely thats not normal. whats supposed to replace the lost water?

does this mean the filling loop needs to be left slightly open?

gdavis

its condense from the combustion process not out of ur system

browner85

where did u drain the system from ?

Gary Busey

browner85 wrote: »

where did u drain the system from ?

Drained from lowest rad. drained upstairs not downstairs. Basically enough to remove leaking valves.

Gary Busey

well I changed the PRV for the sake of 15 euro. repressurised and gonna check the pressure in a few hours so. Fingers crossed.

On another maybe related subnject. I have noticed the pressure rise from 1 bar to 2.2 when hot. Could this be air in the system still?

If so would it be worth my while to completely redrain system and refill slower this time? with inhinbiter of course:)

gdavis

pressure will always rise when heating goes on.are u checking pressure after venting everything?venting without pump running,starting downstairs and working way up?i know it may seem obvious but best off starting at start.when filling /venting complete,did u disconnect filler loops from system?you will also need to wait for aav in hot press to stop hissing as this will meanit is now full.is hpress in attic?if not then it is not highest point on system,rad vents in attic are most probably.where are branches taken off for attic rads?

Gary Busey

gdavis wrote: »

pressure will always rise when heating goes on.are u checking pressure after venting everything?venting without pump running,starting downstairs and working way up?i know it may seem obvious but best off starting at start.when filling /venting complete,did u disconnect filler loops from system?you will also need to wait for aav in hot press to stop hissing as this will meanit is now full.is hpress in attic?if not then it is not highest point on system,rad vents in attic are most probably.where are branches taken off for attic rads?

The aav has not stopped hissing once. seems to Just keep going the whole time. Hot press is upstairs not the attic

gdavis

is there cap on top of aav or mini valve beneath it?if so,close valve or tighten cap.u are getting water from rads in attic?

gdavis

where is boiler situated in house? how many floors?think its time for some pics so we can put this one to bed!! lol

Gary Busey

gdavis wrote: »

is there cap on top of aav or mini valve beneath it?if so,close valve or tighten cap.u are getting water from rads in attic?

there was a cap on top at one stage, not any more as its all corroded and fell off ages ago. Its the standard bottle valve type. And there is water in upstairs heaters. When everything is filled theres no air in the rads whatsoever

gdavis

can u get water pressure up to 2 bar and see if aav is passing water?if its hissing and the rads above it are full then it must be water that u hear.u may have an air lock in system and may need a second person with u to sort out

Gary Busey

3 floors, (converted attic). 22 rads, 3 zones 1 per floor. I promise il take photos in the morning, just got my phone back from vodafone today(non charge) and it has a good camera so I will take photos of all neccessary areas and repost for tomorrow evening.

As for putting this to bed.... please god so I can get some sleep:)

Anyway cheers for your help so far

gdavis

is boiler on bottom floor?i would let pressure up to 2 bar before venting and boost up again after venting to 2 ish for pigiron!!

Gary Busey

gdavis wrote: »

can u get water pressure up to 2 bar and see if aav is passing water?if its hissing and the rads above it are full then it must be water that u hear

I had it up to 2 bar and It wasnt passing water but was moistish.I put a drop of water over it and it filled with air. Not sure if thats correct way of testing but it seemed to work

Gary Busey

gdavis wrote: »

is boiler on bottom floor?i would let pressure up to 2 bar before venting and boost up again after venting to 2 ish for pigiron!!

yes boiler is on bottom floor, I take it i do this at refill stage to force air upwards yes?

gdavis

yes always vent from downstairs to upstairs with pumps off

Gary Busey

I vented one rad downstairs(the one with the drain valve) one rad upstairs(the one closest to the hot press) and 2 rads in the attic as they were the only ones that emptied. All others stayed full as i didnt let air in when draining. I origionally refilled to 1 bar, vented and repeated etc. Mind you, looking at it now i should probably have let air into all rads and fully drained as far as the bottom of the upstairs rad rather trying to cheat:o

gdavis

u did vent every rad in house upon refill? ie ,pressurise to 2 bar,vent all rads on ground floor,check pressure,top back up to 2 bar b4 venting upstairs,check pressure,top up to 2bar b4 venting attic,check pressure,top up to 1.5 bar.ensure all rads are open,is the pressure u are reading at the boiler or on filler loop?where is filler loop located?u sure one of those filler loops hadnt an auto fill valve on it and u have knocked it off?would explain a lot!either one of them has autofill valve or it is taken off cold supply from tank and had been left on,it explains why one filler loop only went to 0.8 bar,thats the reason why,this has been masking the leak in system and u have knocked it off now hence the drop in pressure me thinks!if this is the case there may be no easy fix as leak could be buried in concrete floor,if u leave it connected u are introducing fresh water to system all the time which brings its own problems,[corrosion]

Gary Busey

is this an auto fill valve. Does this add to required pressure?? I have a load of pics here of loops, hot press etc. Il up them soon. I drained entire system added inhibitor and refilled bottom up. Also changed "another":rolleyes: 2 leaky compression joints thats may have added to situation. 1 iss weeping but it wont drop pressure enough to make a difference overnight anyway so fingers crossed. Oh and also change the AAV and 2 filling loops and the 2 NRVs.

I have basiacally removed all the work bar the 3 pumps that another lad fit 1 year ago.

gdavis

yip thats ur autofill valve,the idea is u set that to ,say 1 bar and as water is lost through leaks that tops it up to 1 bar,thus hiding leaks.so now u have ur answer,system has leaks but that was keeping it topped up.u must have turned it off or valve off to it?is there an isolation valve for it?

Gary Busey

gdavis wrote: »

yip thats ur autofill valve,the idea is u set that to ,say 1 bar and as water is lost through leaks that tops it up to 1 bar,thus hiding leaks.so now u have ur answer,system has leaks but that was keeping it topped up.u must have turned it off or valve off to it?is there an isolation valve for it?

Great, I saw a few of them online but nost had knobs to set it. Theres a gate valve below it in the hotpress and what looks like a bleeder screw and after that it hits the main return to the system. No isolation valve bar the gate valve but thats open. Its connected to filling loop and NRV

gdavis

u can adjust that to desired setting by turning brass nut at back,in ideal world all leaks will be accessible and fixable and u can do away with it. u happy that was ur issue anyway?

Gary Busey

gdavis wrote: »

u can adjust that to desired setting by turning brass nut at back,in ideal world all leaks will be accessible and fixable and u can do away with it. u happy that was ur issue anyway?

After I changed all 9 leaks and a few other parts the pressure is steady.
Yep, I am delighted with myself. I will leave the loops off tonight and see what thew craic is tomorrow. Hopefully steady pressure.

Il try adjusting the nut tomorrow to .5 bar and leave the loop a fraction open to account for weeps etc.

Listen mate, cheers for the digout;) I can get some sleep tonight anyway:D:D

gdavis

glad u got it sorted