Testing for a one pipe system

[verdigrey]

I could do with some advice please , A customer has just bought an old bungalow and he has drained C/H system, taken out old S/F stove and taken out the seven old rads . He wants me to quote to fit new Stove and rads . It may be a one pipe system but I am not sure .
2 , I think 22mm pipes disapear under the kitchen floor and just appear at the radiator points .
I told him that if it is a one pipe system it would need changing to a 2 pipe system and feed the rads from above . He is ok with that , but I was wondering what is the easiest way to test if it is a one pipe system or not .
Do you think if I cap off all the pipes except for the 2 to one rad and then connect a hose to one 15mm pipe and if the water comes out of the other 15mm pipe will it mean that it IS a one pipe system ??? Allthough if this is the last rad on a 2 pipe system I quess the water would still go straight thru !!!!
Any ideas please .

 

[SafeGasInstall]

just lift floor boards up aint that hard

 

[PlumbBobBob]

as stan said lift the floorboards only have to do it at one rad you will see if one pipe feeding both valves or two.

 

[verdigrey]

Thanks guys , I should have made it clear , No floor boards , Concrete .

 

[PlumbBobBob]

bit different then lol.

 

[Spanner2k7]

I would do as you said blank off all radiator tails, and connect a hose pipe and fill the system, if it is a one pipe then water will come out of the other pipe.

As the pipes are run in a concrete floor would it not be just worth putting in a new 2 pipe system regardless, as you do not know the condition of the pipes in the floor.

 

[SafeGasInstall]

then do not bother with it just fit new one on drops ! done one last year unvented acumulator and new system boiler ! all run in 22 an the loft then drops to all rooms worked perfect system had if i am not wrong 10 rads as large bungalow in

 

[verdigrey]

Thanks everyone , I may just be able to knock up a bit of concrete in the kitchen as there is work going on there and check wether one or two pipes . Otherwise I will try the water test .
Cheers .

 

[diamondgas]

Verdigrey, If as you say the system is drained and the boiler and all the rads removed why not send some water down the flow. It should come out of just one of the radiator supply pipes unless there's a bi-pass fitted. You could also blow down one (We Engineers like to do that for some strange reason)... Obviously be aware of the black crude that may emerge!

 

[SafeGasInstall]

in this occasion i am a cowboy not engineer

 

[Ultimate P & H]

I would do as you said blank off all radiator tails, and connect a hose pipe and fill the system, if it is a one pipe then water will come out of the other pipe.

As the pipes are run in a concrete floor would it not be just worth putting in a new 2 pipe system regardless, as you do not know the condition of the pipes in the floor.

Water will only come out if the rads have a bypass fitted, otherwise it will come up against the first blanked off pipe and then have nowhere to go. Same thing can be achieved by shutting of any rad valve. If it's a true one piper, you won't get any water flow. Conversely, if it's a one piper with bypasses, shut off all of the rads and you will still get flow, which won't happen on a two pipe system as that relies on one rad being open to maintain circulation.

Armed with the above knowledge and a hose pipe, you should be able to avoid chopping the floor up.

 

[verdigrey]

Thanks everyone for your input . The Guy who has bought the bungalow ( I think he is a builder ) Wants me to only what is really necesary ( he must be a builder ) So i need to show him if it is a one pipe system or not . Armed with your posts I can do this .
Thanks again . P. S. I wont be doing the job for about three weeks yet , but will Post the outcome .