combi on 1 pipe system

[buster gonads]

I know its not the right thing to do but has anybody fitted a combi on a 1 pipe system and it not worked at first but found away round it without changing it to a 2 pipe system, the boiler works fine on DHW but only runs for about 30 secs on heating, thier a old couple and could do without the hassel, thanks in advance, buster.

 

[jpm]

I've done this once on a back boiler replacement.Told customer when quoting about the existing system,they didn't have the cash to replace pipework.Installed WB 30Si 7 rads no probs.Never got a callback so assume all is OK it's about 3 years ago.

 

[migoplumber]

no reason why it shouldnt work, so long as the correct valves are fitted and set up.

shaun

 

[buster gonads]

no reason why it shouldnt work, so long as the correct valves are fitted and set up.

shaun

Shaun, iv,e fitted a byepass but still no joy, what do you mean by correct valves, vokera compact HE by the way.

 

[migoplumber]

i was referring to the radiator valves, its a different valve set up altogether, the individual valve allows hot water to circulate through your radiator leaving you with the ability to turn off said radiator, and still allowing the primary loop to pass through said valve to the next radiator without affecting flow rates.
each valve has a small screw or alan key that adjusts and balances the system changing the flow through the primary loop.
if the primary loop, has too low or high a flow rate, it will upset the boiler. combi boilers get more unhappy about this than system boilers. all to do with temperature differences over flow and return.
i have fitted many combi boilers on one pipe systems (spain likes them) never had a problem with new installs because the system is clean, however i had plenty of calls to similar problems as yours, or a plumber had put in a new boiler and ch had stopped working. plumber hadnt flushed pipes. the fault was always sludge in system.

hope that helps a bit

shaun

 

[buster gonads]

Cheers Shaun, ive had a couple of hours flushing it today but there still seems to be a blockage, it doesnt want to fill properly and takes nearly a hour to drain the 6 rads, its either power flush now or bite the bullet and re-pipe it, re-pipe me thinks, regards.

 

[buster gonads]

Re-piped and updated to 2 pipe system, problem solved. thanks for your input.