H F Posted October 25, 2019 Share Posted October 25, 2019 (edited) It’s been one of those days (and weeks). Earlier today, I saw that the pressure in our expansion vessel had dropped slightly. Hours later, we had a drippy leak in the hallway. I eventually discovered that the expansion vessel pressure was through the roof. I turned the heating off and bled some radiators. That dropped the pressure to where it should be. I turned the heating back on and within an hour the drip started again. I’ve turned the heating off. I assume that a pipe has cracked. Is that a fair assumption? Tomorrow I was going to cut through the wall to see the damage. Any suggestions? Edited October 27, 2019 by Home Farm Link to comment Share on other sites More sharing options...
PeterW Posted October 25, 2019 Share Posted October 25, 2019 Possibly blown a joint or made it weep. Mains can be north of 4 bar, and pipework when it heats can add another bar so 5 bar in your old heating system and something may not like it ... Link to comment Share on other sites More sharing options...
dpmiller Posted October 25, 2019 Share Posted October 25, 2019 you're looking at system pressure, not the pressure in the vessel. Perhaps the bladder has failed in the vessel... Link to comment Share on other sites More sharing options...
H F Posted October 25, 2019 Author Share Posted October 25, 2019 11 minutes ago, PeterW said: Possibly blown a joint or made it weep. Will that need to be soldered? Link to comment Share on other sites More sharing options...
H F Posted October 25, 2019 Author Share Posted October 25, 2019 Just now, dpmiller said: you're looking at system pressure, not the pressure in the vessel. Perhaps the bladder has failed in the vessel... I was referring to system pressure. normally at 1.3-1.5 - hit 2. Bled it back to 1.4. Link to comment Share on other sites More sharing options...
dpmiller Posted October 25, 2019 Share Posted October 25, 2019 but if the expansion vessel has failed, system pressure will alter radically with temperature. Well worth checking the air pressure in the bladder. /that's the tyre valve at the end of the tank. Link to comment Share on other sites More sharing options...
ProDave Posted October 25, 2019 Share Posted October 25, 2019 And you should discharge the system pressure to 0 before checking the AIR pressure in he bladder via the Schroeder valve on the top. If the pressure only got up to 2 bar, then the plumbing is not very good. Link to comment Share on other sites More sharing options...
H F Posted October 25, 2019 Author Share Posted October 25, 2019 32 minutes ago, ProDave said: If the pressure only got up to 2 bar, then the plumbing is not very good. welcome to my world. Sometimes I feel that portions of this house are held together using chewing gum. Link to comment Share on other sites More sharing options...
H F Posted October 25, 2019 Author Share Posted October 25, 2019 Related question - do radiator pipes for upstairs rooms typically run under floorboards or in the wall cavity? Link to comment Share on other sites More sharing options...
H F Posted October 25, 2019 Author Share Posted October 25, 2019 (edited) 39 minutes ago, dpmiller said: but if the expansion vessel has failed, system pressure will alter radically with temperature. Well worth checking the air pressure in the bladder. /that's the tyre valve at the end of the tank. Will do. Thanks for the suggestion. Will google how to do that. Edited October 25, 2019 by Home Farm Link to comment Share on other sites More sharing options...
Onoff Posted October 25, 2019 Share Posted October 25, 2019 (edited) 59 minutes ago, PeterW said: Possibly blown a joint or made it weep. Mains can be north of 4 bar, and pipework when it heats can add another bar so 5 bar in your old heating system and something may not like it ... Our mains pressure is ridiculous, like 8 bar. The main has to come 4 miles uphill up a valley. Traditionally only farms and a few shacks here. Edited October 25, 2019 by Onoff Link to comment Share on other sites More sharing options...
Temp Posted October 25, 2019 Share Posted October 25, 2019 2 hours ago, Home Farm said: Are there no safeguards for expansion vessels doing this? It must be so easy to even accidentally allow it to fill up like this. It's the system pressure you are measuring. There should be a pressure relief valve (PRV) that opens when the pressure gets too high. It should discharge into a tundish (so you can see and hear if it opens) then to the outside of the house. I think our last house had a PRV set to 4 bar but it's a long time ago. Link to comment Share on other sites More sharing options...
Ferdinand Posted October 26, 2019 Share Posted October 26, 2019 (edited) PRV - good things to have working. (See Three Mile Island ?) Sorry about your week, but good to see that your subscribers on the Youtube channel have nearly hit 50. Honest everyday stories are what brings them and keeps them. There a lot of people living in that world who keep stumm, or just ignore it - you are doing a good job ! F Edited October 26, 2019 by Ferdinand 1 Link to comment Share on other sites More sharing options...
H F Posted October 26, 2019 Author Share Posted October 26, 2019 1 hour ago, Ferdinand said: Sorry about your week, but good to see that your subscribers on the Youtube channel have nearly hit 50. Honest everyday stories are what brings them and keeps them. There a lot of people living in that world who keep stumm, or just ignore it - you are doing a good job ! Thanks F. Very kind of you to say that. Going to watch NZ vs England now with incentive of breaking through drywall later to discover leaky pipework. Yay. Link to comment Share on other sites More sharing options...
Ed Davies Posted October 26, 2019 Share Posted October 26, 2019 1 hour ago, Home Farm said: breaking through drywall later to discover leaky pipework. Yay. Your previous question re under floorboards/in wall pipes seems to have been ignored. I'd think radiator pipes are more usually under the floor than in the wall. That's the way it's been done in the few houses I'm familiar with, anyway. Anybody? Link to comment Share on other sites More sharing options...
H F Posted October 26, 2019 Author Share Posted October 26, 2019 Thanks Ed. I figured as much looking at how the pipes come out the wall. Link to comment Share on other sites More sharing options...
joth Posted October 26, 2019 Share Posted October 26, 2019 Afraid it's not much help now the system is not working, but the easiest way to trace central heating pipes is to get the system good and hot then use a thermal imaging camera. (I don't own one but our local council sustainability group have a couple cameras they loan out) Link to comment Share on other sites More sharing options...
ProDave Posted October 26, 2019 Share Posted October 26, 2019 11 hours ago, Home Farm said: welcome to my world. Sometimes I feel that portions of this house are held together using chewing gum. So you know where it leaked,. go and lift a floorboard directly above the leak and have a look. Assuming the central has been retro fitted, you will find floorboards that have previously been lifted when the pipes were installed, so should be easier to lift again to have a look. If you are lucky it will be a compression joint that just needs a bit of tightening. Link to comment Share on other sites More sharing options...
H F Posted October 29, 2019 Author Share Posted October 29, 2019 Located the faulty joint and had it replaced. Central heating is back on. Phew. Link to comment Share on other sites More sharing options...
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