flushing heating pipes

[herbert]

I am in the process of sorting the plumbing out in my brothers 'new' house.. I am in the process of taking out an old primatic system and converting it to a combi (which i am not fitting) i have done all the pipework etc and all the radiators removed and flushed out.. what is the best way to clean the pipework out without a powerflush machine before i change the rad valves and refit the rads? i was thinking of using a 3/4 garden hose connector and connecting it to one of the old valvs and out another flush all the flow pipes with the returns closed and vice verser. I am still new to the plumbing game and i cant think of a better way of doing it. Thanks in advance

 

[Best]

I have just simply joined hoses to 15mm copper by pushing the pipe well inside hose ( helps to put hose end in hot water) & using jubilee clips. You flush whatever way you want, as long as you plug all open vents off & leave other hose connection on.

 

[Best]

Should have said that I join to 15 mm type, tail connection with a nut & olive on end of pipe, but if it is the larger type tail rad valve, I keep a tail with a 15 mm female fitting tightened on it, for to connect to copper pipe on the hose.

 

[herbert]

thanks for the reply but i am not too worried about getting the water to the pipework its more of the process of flushing it out i am not soo sure of

 

[Best]

Trouble is, you have the rads removed, so you have all the " dead runs " to the rads from the main runs to flush. I tend to flush with rads back on. You could always do each pipe at a time, but laborious. Other issue is , how would you know what side of each rad was flow or return. Unless you join flow & return together, temp, somewhere, & then just flush each pipe from one connection?

 

[AWheating]

flushing hot will be better, is the old boiler still connected and working? if so add chemicals and flush out hot.

 

[herbert]

No the old boiler isn't working

 

[maks_rt_011]

Had bad blockage on old open vent system once, without power flashing managed to sort it. Just used my garden hose connecting to garden tap one side another to radiator flow , and another hose connected to radiator return directed to the waste or just outside . Gives you enough pressure to clean sludge out . Just when refiling and running boiler again check pump as might need little help to spin it if got stacked. U can do it by unscrewing front big screw and with our finger or screwdriver just give a little spin. Good luck

 

[herbert]

Success. I connected a garden hose to the 3/4 rad valve and flushed the main run and out the flow pipe which I chopped from the old boiler As it was being replaced, connected a 22 mm gate valve and a 3/4 union nut that was connected to another garden hose to the drain put loads of water through it till it ran clear as soon as it ran clear I opened the flow valves 1 by 1 and ran it till clear. Swapped the garden hoses on to the returns and did the same. it was a long job but necessary as the old system was not maintained at all. Thanks all for the replies and advice