How long to power flush

[ARLester]

Hi guys.
a few questions.
I’ve got a blocked system and am looking at a power flush to resolve it. Heat is getting to the flow tails and into the rads but I’d say at 50% of what they should be. Had a plumber attained and do everything possible ie check valves, TRVs, cleaned out rads with a hose etc therefore the conclusion is the blockage is in the 15mm plastic pipework somewhere.

1) how long would you estimate to power flush just 5 rads (remembering there’s a blockage)
2) would you crack on all day if you hadn’t had a result in a few hours ? Or would you assume if it hadn’t shifted in a few hours, it wasn’t gonna get shifted?
3) given the ideal result is to clear a blockage rather than just cleanse the system, how much would you charge ?

cheers

 

[Ric2013]

1. Assuming there weren't a blockage, 10 hours? Add your blockage... hard to say.

2. I wouldn't know if I'd had a result until afterwards as it's not really possible to know how things will be once normal operation resumes.

3. Cost of work depends largely on location so I can't comment. Flushing equipment is expensive so expect to pay for labour, chemicals, and extra the because flushing equipment is coming out.

 

[ARLester]

1. Assuming there weren't a blockage, 10 hours? Add your blockage... hard to say.

2. I wouldn't know if I'd had a result until afterwards as it's not really possible to know how things will be once normal operation resumes.

3. Cost of work depends largely on location so I can't comment. Flushing equipment is expensive so expect to pay for labour, chemicals, and extra the because flushing equipment is coming out.

Thanks Ric. Appreciate the response. I’m east London based.

 

[Riley]

It is unfortunately a how long is a piece of string exercise. Is it definitely a blockage??

 

[SJB060685]

It largely depends on the extent of corrosion and the volume of built up magnetite and iron oxide.
Even for a relatively clean and small system i would allow a whole day.
I dud once however find a system so badly corroded that the internal bore of all the 22mm pipe was about 2-3mm, thats no lie, the extent of corrosion in that system has never been witnessed by either since or before again.
In this particular example it was more beneficial to wrip all the pipework out, replace with new and rectify the cause of corrosion. So as I say it depends not only on size but the level of buildup as well.

 

[ARLester]

It is unfortunately a how long is a piece of string exercise. Is it definitely a blockage??

Hi Riley and thanks for picking up on this. It’s 100% a blockage and all avenues have been tried to date ie mains pressure / take of rads / chems etc.

 

[cjg]

a good cleaner in, run for 1 week, check filter ON boiler, and normal flush both ways through boiler most times sorts it, refill , add inhib, job done.

 

[Chuck]

Hi Riley and thanks for picking up on this. It’s 100% a blockage and all avenues have been tried to date ie mains pressure / take of rads / chems etc.

You'll need to replace or bypass the blocked section before flushing or you'll be wasting your time.

 

[SimonG]

What plastic pipe is it? If it's the old non barrier pipe you're in trouble.

 

[jh2254]

You'll need to replace or bypass the blocked section before flushing or you'll be wasting your time.

Or spend weeks rodding the pipes to get them cleaned enough for the cleaner to get through! , which is what I did ! 😩

 

[jh2254]

What plastic pipe is it? If it's the old non barrier pipe you're in trouble.

Interested to know what old barrier pipe is? I rodded my old plastic pipes but had no idea if they were 'non barrier'? Also why would you ever install 'non barrier' in the first place? Thank you.

 

[SimonG]

Interested to know what old barrier pipe is? I rodded my old plastic pipes but had no idea if they were 'non barrier'? Also why would you ever install 'non barrier' in the first place? Thank you.

Original plastic pipe did not have a barrier layer to prevent ingress of oxygen.
Originally it was all that was available. No issue on potable supplies but an absolute nightmare now on some heating installations.