Big problems with heating system.

[LeakFinder's]

i had a call from a potential customer yesterday.
He has a 3500sq ft bungalow with 28 rads in 4 zones. the house is around 18 years old. he has replaced nearly all the radiators to date some have been replaced twice. The heating system would have been topped up every three months but he is topping it up every other day ( the leak is the easy bit ). He advises that a heating engineer removed the 4 small pumps and replaced with a single large pump and power flushed the system for 2 hours and fitted a magnaclean and put inhibitor in the system ( not the best flush performed ). The system is oil fired and sits at 0.5 bar cold and when run up expands to 1.5bar. He advises that each engineer that has visited has replaced the pressure vessel with a larger one. i think he has went from a football to a space hopper as far as the vessel goes. It would appear that corrosion has been a problem for a while and topping the system every 3 months. Though not good i don't think this would have resulted in all the rads being replaced over the last 10 years. I asked regards bleeding the rads and he says he just ever tops the system but no bleeding. the only reason i am interested in the job is that the fault appears unusual and what would be classed as reputable heating engineers haven't solved it. i have only bits and pieces of info as yet. I had a job similar to this around 3 years ago and it was a water born bacteria which became active at temperature the boiler and all rads were replaced and an aggressive tratment appears to have been used to kill off the bacteria. thanks in advance guys for any ideas

 

[goz666]

I've read that three times now mate and I don't understand the question ??? What exactly is the problem if the leak is the easy bit ???

 

[fnose]

i dont understand the question either mate, two things u could do, fix leak get paid go home, sample ch water and treat as required.

 

[Nostrum]

Is the cold water fed off the main?

 

[LeakFinder's]

ok Guys,
the man has lived in the house for ten years over that period he has replaced all the radiators some twice. He has had a leak over the last 6 years which involved topping the system up every 3 months recently that is down to every other day. Would replacing all the rads. Some plumber has also taken out the 4 smaller pumps and put in a larger pump which causes the system to sit at 0.5bar cold and expand to 1.5bar.
Questions:
1/ I realise things like flux and lack of maintenance will cause damage to the heating system but is their anything else I should be looking for ?
2/ The guy started off with a pressure vessel about the size of a football and aparently has been changed 4 times by plumbers and is bordering on the size of a space hopper and yet still expands from cold by over 1 ba. Is their any other causes other than resistance?

sorry the first post was a bit vauge.

 

[dancinplumba]

has pressure vessel got the right air pressure in it ? does it have water softener ?

 

[LeakFinder's]

Sorry forgot to mention sys is pressurized. I am concerned at the ongoing damage and how to stop it ?

 

[Nostrum]

Expanding 1 bar is perfectly acceptable, your heating water, so you will always have expansion. I can't see the pump configuration having much affect on the pressure either. Somethings rotting the rad's out, If the rad's have been changed so often then it must have been drained a few times in its life (10 years). Mosrt oil boilers are cast so I would expect his boilers knackered aswell if its that bad.

 

[Nostrum]

Is the cold water on the main? had similar with a few places around here that are feed off private supplies (wells etc) and they have had to have stainless steel water cylinders as they only last about 3-4 years due to contaminants

 

[Best]

Should be simple if you know where all the leaks are. Just fix them & make sure the vessel is right size & has correct air charge.
Take care all valves do not have micro leaks at packing & that compression joints have no tiny weeps.

Forgot to mention to make sure the PRV - pressure relief valve is not letting some water pass.

 

[LeakFinder's]

best, yea going seperate out and p test aroud 4 bar see where we goto. see you also ni just new to the forum. i am county down.

 

[Roger Welton]

If its a large system, has the correct dose of inhibitor been added each time its been drained? i.e. not just one bottle.

 

[scotty plumber]

28 rads that scare's me!

 

[Best]

best, yea going seperate out and p test aroud 4 bar see where we goto. see you also ni just new to the forum. i am county down.

Don't pressure test anything other than pipes above 2 or 3 bar as rads & boilers are not supposed to be more, & you dont need more anyhow for test.

Yes, I am sitting in Co. Down at the minute, - Comber, to be precise. I am from Co. Antrim.

 

[LeakFinder's]

i only spoke to him friday but yea 28 rads will take a bit more than a 1 or 2 ltr dose treatment. i will test the water and hopefully get an indication of state and work from their. its a pain in the rear when someone gets paid good money for say a flush and treatment and they do it half hearted or skimping on product and the problems still go on.

 

[LeakFinder's]

I did ask the question re supply. We had a job last year where a mains leak kept tripping the well pump. The house was built 2 years and the mains supply had perforation. I asked was the water tested before use typical farmer "no" and his wife wondered why the 2 daughters were always sick if that is what it done to pipes in 2 years i dread to think what it will do to a person