What product to use for chemical flush?

[jaretti]

Hi,

Have been having problems with few noisy radiators, particulary one in master bedroom which wakes us up when heating is on. Also most of rads are not hot at the bottom. Obviously all rads are bled and reasonably balanced.

Oil central heating, conventional boiler. Old copper pipework that runs in the concrete floor, so power flush is not an option as pipework won't hold the pressure.

Unfortunately only drain point is above the floor while pipework runs under, so can't completely flush the system. Thinking of doing chemical flush, not sure which product is better for my problem, as I'm really worried about damaging old pipework if using something thats too aggressive.

Any ideas, please?

 

[Exedon]

Sentinel X400

 

[Harry Bloomfield]

Have been having problems with few noisy radiators, particulary one in master bedroom which wakes us up when heating is on.

If the noise is a ticking, as the radiator heats up, and expands, then probably that is metal, rubbing on the metal brackets, because they are lacking the U shaped plastic inserts, between the two. If it's a water gushing noise, that will be due to sediment restrictions, in the radiators.

Also most of rads are not hot at the bottom.

Radiators, when there is little demand for heat, will only get hot at the top. Is it the same with the room stat set high?

Unfortunately only drain point is above the floor while pipework runs under, so can't completely flush the system.

If the radiators are choked up, it might be worth your while, removing them one at a time, taking them outdoors, and giving them a thorough flush through, before replacing.

Could perhaps add more under-floor drains to pipes? If your radiators are as choked as you suggest, likely the pipes will be too.

 

[jaretti]

Sentinel X400

Thanks. How long would you leave it for?

 

[jaretti]

If the noise is a ticking, as the radiator heats up, and expands, then probably that is metal, rubbing on the metal brackets, because they are lacking the U shaped plastic inserts, between the two. If it's a water gushing noise, that will be due to sediment restrictions, in the radiators.

It's both really, depending how much lockshields is open on the rad. Do you mean metal brackets for hanging radiator on the wall?

If the radiators are choked up, it might be worth your while, removing them one at a time, taking them outdoors, and giving them a thorough flush through, before replacing.

this particular rad has been replaced in April, don't expect it to be completely choked up

 

[Harry Bloomfield]

Do you mean metal brackets for hanging radiator on the wall?

Yes!

this particular rad has been replaced in April, don't expect it to be completely choked up

It could therefore be restriction in the pipe, due to sediment, not allowing adequate flow to the radiator. The is nothing amiss with my radiators, or pipework system, but my radiators only get hot at the top, at the moment, because the demand for heat is minimal at the moment - heated water, entering a radiator, immediately rises to the top of the radiator. If the heated water continues to flow in, the heat will spread down in the radiator.

 

[jaretti]

Yes!



It could therefore be restriction in the pipe, due to sediment, not allowing adequate flow to the radiator. The is nothing amiss with my radiators, or pipework system, but my radiators only get hot at the top, at the moment, because the demand for heat is minimal at the moment - heated water, entering a radiator, immediately rises to the top of the radiator. If the heated water continues to flow in, the heat will spread down in the radiator.

You might be right about brackets. We have a 3 column rad sitting on 6 metal brackets. I wonder if I could insert something in between to test that theory...

 

[Harry Bloomfield]

You might be right about brackets. We have a 3 column rad sitting on 6 metal brackets. I wonder if I could insert something in between to test that theory...

Take a piece of twin and earth cable, slit it via one of the edges, extract, and discard the cable, cut the grey plastic into short pieces, and insert on the U of the bracket.

 

[endecotp]

I wonder if I could insert something in between to test that theory...

Search for something like "radiator bracket plastic inserts".

 

[spile]

Thanks. How long would you leave it for?

48hours ish

 

[Exedon]

Thanks. How long would you leave it for?

To be clear sentinels instructions for X400 say up to 4 weeks for badly fouled systems.
Also there is no time limit on how long it can be left in system.