Ballpark cost to reposition CH pipes

badger09

Moved here in February, 4 bed detached bungalow with bathroom & 2 small ensuites. Built early 70's by respected local builder who lived here many years, and 2 subsequent extensions.

New boiler fitted in September is losing pressure. No obvious leaks or visible damp and our engineer thinks its due to leak in pipe somewhere under the solid floors.

I've calmed down a bit and specialist tracing company is coming 15th to find it. I'm prepared for having to have floor dug up (just hoping it isn't under tiled kitchen/diner or newly carpeted & decorated living room).

Once its fixed, I feel we would be living with a time bomb waiting for it to happen again, so wondered if anyone could give a ballpark figure to reposition all the pipes so that at least we can see any leaks in future.

Bendy_House

These pipes would now be surface run? Eek.

When the current leak is hopefully found, it'll also hopefully be obvious what the cause of the leak was. It could be a badly-made solder joint, for instance. If so, and if the pipes are otherwise protected in the concrete floor as they should be, relax.  

badger09

Bendy_House said:

These pipes would now be surface run? Eek.

When the current leak is hopefully found, it'll also hopefully be obvious what the cause of the leak was. It could be a badly-made solder joint, for instance. If so, and if the pipes are otherwise protected in the concrete floor as they should be, relax.  

To be honest, I would always worry that this could happen again. I'd much rather avoid that if at all possible. 

oystercatcher

badger09 said:

Bendy_House said:

These pipes would now be surface run? Eek.

When the current leak is hopefully found, it'll also hopefully be obvious what the cause of the leak was. It could be a badly-made solder joint, for instance. If so, and if the pipes are otherwise protected in the concrete floor as they should be, relax.  

To be honest, I would always worry that this could happen again. I'd much rather avoid that if at all possible. 

There is a small '80's development in our town where it is well known that most of the houses were built with substandard copper pipe , due to a shortage at the time. So many of the houses have had similar under floor leakages. When my parents bought a bungalow in this area they were assured that the issue had been fixed and pipes all replaced. However the problem did reoccur and on the third event they had all the pipes rerouted through the loft. I must admit the pipes on the walls look terrible but it has fixed the issue . I'm afraid I have no idea of the cost but just sharing experience. This problem can and does reoccur!

nofoollikeold

1. First step is to be certain its not the boiler.  Under the boiler there will be valves to isolate the boiler's flow and return pipes.  These are usually the 22 mm pipes at each end of the boiler, but not always so check the installation instructions for your boiler.  Pressurise the system to 1.5 bar, then close both valves.  Don't run the boiler for as long as you can stand, but a minimum of 12 hours.  If the pressure drops with the valves closed, the fault is in the boiler.  If is drops when the valves are reopened, its in the system.
2. If its in the system, then I'm afraid in all likelihood its the pipework (assuming copper) being attacked by the alkali in concrete.  In my view its highly unlikely that a badly made joint would suddenly decide to leak after some years.
3. If its a problem of "copper rot" it is very likely to keep recurring, generally close to the first occurrence.  Once the concrete gets wet it accelerates the impact on copper.  You probably have two alternatives:
3a. Re-route all pipes through the loft which will give you the problem of hiding the drops to the radiators.
3b. Dig up all the floors and either replace the copper with plastic piping, or lay new copper properly protected.  
4. Costs all depend on layout and access.  Assuming 10 radiators, and you doing the making good, I'd guess between 2 and 3 man days, plus the copper piping and fittings.  London suburbs - around the £1700 to £2000 mark.  Very rough guesstimate.

badger09

nofoollikeold said:

1. First step is to be certain its not the boiler.  Under the boiler there will be valves to isolate the boiler's flow and return pipes.  These are usually the 22 mm pipes at each end of the boiler, but not always so check the installation instructions for your boiler.  Pressurise the system to 1.5 bar, then close both valves.  Don't run the boiler for as long as you can stand, but a minimum of 12 hours.  If the pressure drops with the valves closed, the fault is in the boiler.  If is drops when the valves are reopened, its in the system.
2. If its in the system, then I'm afraid in all likelihood its the pipework (assuming copper) being attacked by the alkali in concrete.  In my view its highly unlikely that a badly made joint would suddenly decide to leak after some years.
3. If its a problem of "copper rot" it is very likely to keep recurring, generally close to the first occurrence.  Once the concrete gets wet it accelerates the impact on copper.  You probably have two alternatives:
3a. Re-route all pipes through the loft which will give you the problem of hiding the drops to the radiators.
3b. Dig up all the floors and either replace the copper with plastic piping, or lay new copper properly protected.  
4. Costs all depend on layout and access.  Assuming 10 radiators, and you doing the making good, I'd guess between 2 and 3 man days, plus the copper piping and fittings.  London suburbs - around the £1700 to £2000 mark.  Very rough guesstimate.

Thank you for the detailed response. Our CH engineer who fitted the boiler in September, is Worcester Bosch accredited  so I assume he would have ruled out any potential boiler issues? A plumber sent by Homeserve to check, also said he couldn't see any problem with the boiler.

We've definitely decided we don't want to go through this again, so will have the pipes rerouted. We have 11 radiators & 2 plumbed in towel rails, but are in Shropshire. Both in our 70s with limited DIY skills, so I'll budget a bit more for 'making good'. It will be worth it for peace of mind.

Thanks again