Home |
Search |
Today's Posts |
|
UK diy (uk.d-i-y) For the discussion of all topics related to diy (do-it-yourself) in the UK. All levels of experience and proficency are welcome to join in to ask questions or offer solutions. |
Reply |
|
LinkBack | Thread Tools | Display Modes |
#1
Posted to uk.d-i-y
|
|||
|
|||
Combi Boiler Pressure Drop
First of all I know very little about boilers, so please be patient!
Having got a decorator to remove and drain out a radiator so as he could paint behind it, on reconnecting and turning the hot water inflow back on, we noticed the pressure on the system drop from about 1.2 to almost zero. This didn't surprise him as basically we took out a fair proportion of the water in the system (total of 4 radiators in our flat). Problem is now we can't see away of replenishing the water back in. Examining the pipe work underneath the boiler, the chap helping me saw that the two pipes to the RHS of the photo below should be connected by the flexible silver pipe just hanging over it! http://www.philrichards1.pwp.blueyonder.co.uk/Boiler.jpg At that point he gave up and said to get expert advice! Fortunately we have a fixed service contract with British Gas who only 7 months ago carried out a service check and presumably this didn't appear out of the norm. They are due out Monday morning. On speaking to someone else, from my descriptions he reckoned the system is sealed. There is no water tank in the loft, all water comes in from the mains and he reckoned sometimes once a boiler like this is set up and the system filled up with water, often the water supply is disconnected. So my questions a 1. The boiler seems to run OK on a much lower pressure, with the radiators at their normal heat. The only difference is you can hear air in the system. Is it safe to keep the system running this until the engineer comes out Monday, especially as the current cold weather is forecast for the weekend? 2. How on earth is a system supposed to be refilled easily when radiators are drained out? Or is there another way of allowing mains water into the system. 3. How easily would it be for the engineer to get the pressure back? I only hope that especially as British Gas have already examined the system (on two occasions, once after it developed a fault, the other a service check) they will not say I've tampered it or it is a design fault. Many thanks. -- Phil Richards London, UK Home Page: http://www.philrichards1.pwp.blueyonder.co.uk |
#2
Posted to uk.d-i-y
|
|||
|
|||
Combi Boiler Pressure Drop
Owain wrote:
http://www.philrichards1.pwp.blueyonder.co.uk/Boiler.jpg 2. How on earth is a system supposed to be refilled easily when radiators are drained out? Or is there another way of allowing mains water into the system. By connecting the flexible silver pipe between the cold water main and the radiator circuit, and turning the taps on until the pressure gauge goe up to whatever it should be. Are you saying there are now no screw-on connection points for the flexible pipe? 3. How easily would it be for the engineer to get the pressure back? Very easy assuming there are screw-on connection points for the flexible pipe. I don't know what British Gas will say - be prepared for them to tell you you need a new boiler. Perhaps not too clear from the photo I took, there are screw on connections on both pipes on the RHS. I can see now how easy the job will probably be. What I don't understand is why they effectively got sealed off presumably after the boiler and radiator system were installed making it difficult to top it up after, say what I did, by draining out one radiator. I don't know what British Gas will say - be prepared for them to tell you you need a new boiler. Well I hope not..... -- Phil Richards London, UK Home Page: http://www.philrichards1.pwp.blueyonder.co.uk |
#3
Posted to uk.d-i-y
|
|||
|
|||
Combi Boiler Pressure Drop
In message , Phil Richards
writes Owain wrote: http://www.philrichards1.pwp.blueyonder.co.uk/Boiler.jpg 2. How on earth is a system supposed to be refilled easily when radiators are drained out? Or is there another way of allowing mains water into the system. By connecting the flexible silver pipe between the cold water main and the radiator circuit, and turning the taps on until the pressure gauge goe up to whatever it should be. Are you saying there are now no screw-on connection points for the flexible pipe? 3. How easily would it be for the engineer to get the pressure back? Very easy assuming there are screw-on connection points for the flexible pipe. I don't know what British Gas will say - be prepared for them to tell you you need a new boiler. Perhaps not too clear from the photo I took, there are screw on connections on both pipes on the RHS. I can see now how easy the job will probably be. What I don't understand is why they effectively got sealed off presumably after the boiler and radiator system were installed making it difficult to top it up after, say what I did, by draining out one radiator. I understand that it is correct for the silver tube to be removed but, usually, you can just screw it back on and open the taps to fill the system. Are the pipes capped and sealed? Or will the caps pop off to allow you to screw the pipe on? -- Richard Faulkner |
#4
Posted to uk.d-i-y
|
|||
|
|||
Combi Boiler Pressure Drop
Phil Richards wrote:
All the information and some background as to how your system works can be found he http://www.makewrite.demon.co.uk/SealedCH.html So my questions a 1. The boiler seems to run OK on a much lower pressure, with the radiators at their normal heat. The only difference is you can hear air in the system. Is it safe to keep the system running this until the engineer comes out Monday, especially as the current cold weather is forecast for the weekend? Depends on how low the pressure is... some boilers will refuse to fire without enough in the system. Sounds like yours is running OK though. 2. How on earth is a system supposed to be refilled easily when radiators are drained out? Or is there another way of allowing mains water into the system. Via the "filling loop" (i.e. that hose of yours). There are two connection points: one is a tap - this is on the cold main supply. The other is a non return valve on the heating system. This lets water into the heating system but not out. The only slight extra wrinkle with your setup is it looks like someone has screwed caps onto the filling loop connection points. This is no bad idea since it keeps dust and other crud out of the ends of the valves etc. You should find the caps unscrew easily by hand. No water should come out when you take the caps off. It is "correct" to disconnect the filling loop once the system is filled. (basically it is another safeguard that prevents any possibility of contaminanted dirty water out of your heating system getting back into the drinkable mains supply) 3. How easily would it be for the engineer to get the pressure back? I only Very easy. Connect up the loop and open the tap. Watch the pressure guage and turn off when at the right pressure. Bleed any air from the radiators. Top up the pressure if neccessary. Repeat until there is no more air to bleed. See the FAQ for a full description. hope that especially as British Gas have already examined the system (on two occasions, once after it developed a fault, the other a service check) they will not say I've tampered it or it is a design fault. No, your system looks fine. Topping up the pressure is one of those tasks that you will usually only need to do should you remove rads etc. -- Cheers, John. /================================================== ===============\ | Internode Ltd - http://www.internode.co.uk | |-----------------------------------------------------------------| | John Rumm - john(at)internode(dot)co(dot)uk | \================================================= ================/ |
#5
Posted to uk.d-i-y
|
|||
|
|||
Combi Boiler Pressure Drop
In article ,
Phil Richards writes: Perhaps not too clear from the photo I took, there are screw on connections on both pipes on the RHS. I can see now how easy the job will probably be. What I don't understand is why they effectively got sealed off presumably after the boiler and radiator system were installed making it difficult to top it up after, say what I did, by draining out one radiator. The filling loop must be disconnected when not being used. This is to prevent any remote chance of the radiator water getting back into the fresh water supply. I can't see clearly in the photo, but the supply end should have a tap and the heating end should have a one-way valve to prevent water coming back out. -- Andrew Gabriel |
#6
Posted to uk.d-i-y
|
|||
|
|||
Combi Boiler Pressure Drop
John Rumm wrote:
Phil Richards wrote: All the information and some background as to how your system works can be found he http://www.makewrite.demon.co.uk/SealedCH.html snip No, your system looks fine. Topping up the pressure is one of those tasks that you will usually only need to do should you remove rads etc. Many thanks to John, Owain & Richard for all their help. I must say out of the many newsgroups I read this seems to be one of the friendliest & most helpful! -- Phil Richards London, UK Home Page: http://www.philrichards1.pwp.blueyonder.co.uk |
#7
Posted to uk.d-i-y
|
|||
|
|||
Combi Boiler Pressure Drop
On Sat, 19 Nov 2005 11:20:28 +0000, me9 wrote:
On 19 Nov, (Andrew Gabriel) wrote: The filling loop must be disconnected when not being used. This is to prevent any remote chance of the radiator water getting back into the fresh water supply. I can't see clearly in the photo, but the supply end should have a tap and the heating end should have a one-way valve to prevent water coming back out. It must be one of a few that comply. Most seem to leave the filling hose connected. There appears to be a tap on the right of the photo , over which the hose iis draped. It looks as if the filling point and supply are capped with brass compression stop ends. More likely 1/2" BSP brass caps. This year a boiler I had installed was inspected and was told that I had left the filling loop connected. I was sent a letter telling me to go and disconnect it. I disagree that the best practice is to disconnect the loop, but that's what our lords and masters require, eh. A small quantity of water dribbles out of the loop after disconnection (OK so you can use a cloth to catch it). Also a small amount of air is introduced into the system when it's reused. Also dust caps are not supplied with most filling loops so these have either to be supplied or the possibility of 'foreign' matter getting in has to be endured. -- Ed Sirett - Property maintainer and registered gas fitter. The FAQ for uk.diy is at http://www.diyfaq.org.uk Gas fitting FAQ http://www.makewrite.demon.co.uk/GasFitting.html Sealed CH FAQ http://www.makewrite.demon.co.uk/SealedCH.html |
#8
Posted to uk.d-i-y
|
|||
|
|||
Combi Boiler Pressure Drop
In article .uk,
Ed Sirett writes: I disagree that the best practice is to disconnect the loop, but that's what our lords and masters require, eh. A small quantity of water dribbles out of the loop after disconnection (OK so you can use a cloth to catch it). Also a small amount of air is introduced into the system when Yes. I connect up the supply end first and very loosely connect the heating end, turn on the water so it blows most of the air out of the loose connection, before tightening it up to force the water through to the heating system. it's reused. Also dust caps are not supplied with most filling loops so these have either to be supplied or the possibility of 'foreign' matter getting in has to be endured. or of young enquiring minds thinking "what happens if I turn this knob?" ;-) Mine's in a rather shallow cupboard, and the door won't stay shut if the filling loop is left connected anyway. -- Andrew Gabriel |
#9
Posted to uk.d-i-y
|
|||
|
|||
Combi Boiler Pressure Drop
On Sat, 19 Nov 2005 01:19:04 +0000, Richard Faulkner
wrote: Are the pipes capped and sealed? Or will the caps pop off to allow you to screw the pipe on? From the photo, it looks like they are indeed sealed with brass, threaded caps. |
#10
Posted to uk.d-i-y
|
|||
|
|||
Combi Boiler Pressure Drop
On Sat, 19 Nov 2005 00:51:52 +0000, Phil Richards wrote:
Owain wrote: http://www.philrichards1.pwp.blueyonder.co.uk/Boiler.jpg 2. How on earth is a system supposed to be refilled easily when radiators are drained out? Or is there another way of allowing mains water into the system. By connecting the flexible silver pipe between the cold water main and the radiator circuit, and turning the taps on until the pressure gauge goe up to whatever it should be. Are you saying there are now no screw-on connection points for the flexible pipe? 3. How easily would it be for the engineer to get the pressure back? Very easy assuming there are screw-on connection points for the flexible pipe. I don't know what British Gas will say - be prepared for them to tell you you need a new boiler. Perhaps not too clear from the photo I took, there are screw on connections on both pipes on the RHS. I can see now how easy the job will probably be. What I don't understand is why they effectively got sealed off presumably after the boiler and radiator system were installed making it difficult to top it up after, say what I did, by draining out one radiator. Because you are NOT supposed to leave the flexi pipe permamantly connected, although everyone actually does. |
Reply |
Thread Tools | Search this Thread |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Forum | |||
New condensing boiler installation - truth or lies | UK diy | |||
Membership requirements? | Woodworking | |||
*** Rec.Woodworking Mini-FAQ *** 145, Now with less transfat! | Woodworking | |||
*** Rec.Woodworking Mini-FAQ *** 140, Certified BSC Free! | Woodworking | |||
Automatic water pressure maintainer for combi boiler system? | UK diy |