system pumping over

[bluegambler]

My system is pumping over - seems to be when the heating and /or hot water are on.
How can I solve this please?
Would flushing the system through help?

I can probably raise the ex tank by a foot - would that help.

The pump is on lowest speed.

 

[JohnD]

how long has it been doing that?

what has happened since it last worked OK?

for a start, buy a litre of Sentinel X400 to add to the tank. It will cost you about £15. Don't buy a cheaper substitute.

While that's working for the next few weeks, find the drain cock, bleed the radiators, and look at the colour of the radiator water (1) today (2) after the X400 has been circulating for a week.

Can you do basic DIY plumbing?

How old is the system?

When was an anti-corrosion chemical last added, and what was it? Has the system been drained and refilled since then? Does it drip or leak?

 

[bluegambler]

seems to have been doing it over the last 12 months.
pump speed already on lowest

is this sentinel x 400 ok on old systems ( system about 25 years old - Potteron Flamingo) - dont want to cause any leaks.

I can do basic plumbing.

Many thanks for your help

 

[simond]

Causes of pumping over;

1. Pump speed
2. Blocked cold feed and or pipework restricted in this area
3. Poor pipework design
4. Feed and expansion tank too low in relation to system pipework

From what you have said, it is likely to be (2), as 3&4 would have been an issue from day one.

If so, you need to cut out the cold feed open vent junction and repipe. No amount of Sentinel X400 will sort it.

 

[bluegambler]

thanks for that.

Do you think the ex tank is too low, its about 7' above the cylinder/pump/ mot valves.

I will try a quick flush through to see if it helps.

 

[Mark Br]

I'm with Simond

Try putting a magnet where the cold feed tee's in, if it sticks to the pipe there's your blockage, cut out and replace.

 

[JohnD]

A quick flush with plain water will do no good at all.

A sludge-loosening chemical may help, and will certainly do no harm. There is probably quite a bit of sludge present throughout the system, not just at one point. From what you say the water is coming up the vent and going down the F&E pipe, so you still have circulation past the constriction. You can add the chemical straight away while you get round to draining and cutting. Yes, X400 is non-aggressive and will not attack your old boiler or pipes.

I agree finding and cutting out the section with the partial blockage is the right solution, and it probably will be the Tee where the 15mm F&E pipe joins the 22mm circulation pipe. A magnet will help you. You also have to clean out all the rest of the sludge and sediment.

 

[45yearsagasman]

View media item 39013Your system may resemble this configuration.

 

[bluegambler]

Thanks all for your comments. I have drained some water from a radiator and very brown water came out. I will get some chemical desludger Sentinel. Whats the best inhibitor to put in please once the system has been refilled.

 

[JohnD]

Sentinel X100 is good. Add it on the final fill after you have done all repairs, cleaning, drained and rinsed. It wil inhibit future corrosion, but it will not remove the existing.

The brown water indicates rust from the insides of the radiators. When you add the X400 sludge loosener, the water is likely to go black, this is from the existing black sediment being washed around by the circulating water. After running X400 for a few weeks, you drain it out and rinse, this will wash out the loosened sediment.

Because the system has been pumping over, oxygen has been dissolving in the water which speeds up corrosion especially the brown rust.

 

[Agile]

I dont know why anybody suggests X400.

X800 does the job in just 4 hours!

Better to drain the old dirty water out before adding the cleanser.

I am surprised none of the rads have not started to leak yet.

Easier to cut out the pipe where the vent and feed join the CH. This will probably be needed anyway!

Tony

 

[Agile]

I dont know why anybody suggests X400.

X800 does the job in just 4 hours!

Better to drain the old dirty water out before adding the cleanser.

I am surprised none of the rads have not started to leak yet.

Easier to cut out the pipe where the vent and feed join the CH. This will probably be needed anyway!

Tony

 

[bluegambler]

ive got a cyltrol valve (see photo), a cylinder stat and 2 m valves. I think the head of the cyltrol valve is broken and ceased - it is hot under the valve and cool above. If I took the valve out or replaced it, do you think it would solve (or help) my pumping over issue.

 

[JohnD]

the cyltrol should be on the return, not on the flow. Is it?

if you take off the blue plastic cap, you may be able to grip the knurled brass stem and turn it fully open.

 

[bluegambler]

not sure if it is a cyltrol valve. Have started to unscrew black head, and it slowly reveals pressure readings as it goes up the stem 0.5 bar, 0.4 bar, etc
Can I screw the head completely off - dont want to cause a leak

Untitled

• bluegambler
• 7 May 2012
• 3