unblocking sludge choked pipework in central heating system

[sandys]

hot water supply pipe to a radiator is absolutely blocked and no liquid will flow through it. Have checked that the valve at the radiator is not faulty.
Supply pipe lies in a totally inaccessible area. mains pressure will not move the blockage. Is their some way I could apply suction or alternatively are gadgets available which will allow me to drill out the blockage ( like the systems used to unblock drains. The system is heavily contaminated with sludge and eventually will require chemical desludging. I'm told the chemical desludger will not help with this current problem

 

[colinand]

I am busy unblocking my microbore pipes. I discovered that the blockage is always near the beginning where the microbore comes off the manifold connected to the larger bore supply pipe. I presume the temperature drops and possibly there's also a stagnant reservoir there. I was able to unsolder the microbore at straight couplings about 20cm from the manifold and poke stiff wires along - bicycle spokes are good. The crust was hard and difficult to dislodge but I managed it eventually. I've replaced the soldered couplings with compression ones so I can do it again if need be though hope this time to keep a better watch on my corrosion inhibitor - the last lot worked for 10 years and even though I have no connection to the mains so couldn't become diluted, it did stop working eventually.

 

[Agile]

You can only "suck" to one atmosphere whereas you can apply pressure at many atmospheres.

Only physical intervention is likely to work although mineral acids at high pressures might but would be extremely dangerous!

Tony

 

[Nige F]

You can only "suck" to one atmosphere whereas you can apply pressure at many atmospheres.

Ye cannae change the laws o` physics, Jim

 

[sandys]

Thanks for your suggestions. I appear to have 90 degree bends in the plastic pipework and its there that the gravel, must be ferrous oxide, rather than sludge has gathered. Need to take up a floor or knock a wall down to get at it. Maybe an electric replacement heater would be both cheaper and less aggravation.

 

[ChrisR]

Maybe an electric replacement heater would be both cheaper and less aggravation.

That's what some landlord's decide!

Obvious really but if you apply the mains at the radiator end you stand a better chance of getting something moving. You could also hire a pressure test pump (cheap), and pump up to say 10 bar or whatever you reckon the pipes will stand before she blows, jim.