Heating problems

[srhawksy]

Hi, I have been trying to get a central heating system working but cant seem to fix the problem, hoping for some advice!

Here's what's what;

The system is open vented with gravity primaries and pumped C/H. The boiler is an old ideal e-type, pump on the return.
The C/H doesn't work, the rads do not heat up properly, the only one that heats up is adjacent the boiler in the kitchen (seems to be making a circuit through conduction in the water). I've tried balancing the system and can never get all rads working at the same time.
The boiler is kettling cutting out cooling down firing up kettling and so on.
I tried changing the pump so that's new, no change.

It seems that the water isn't circulating as the flow does eventually heat up and the flow will get piping hot all the way to each rad but there is no where near the same amount of heat going through the rads or coming back on the return. the f/r come out of the boiler go down under the floor in the kitchen around to the downstairs rads then up in the living room to feed upstairs rads

I have power flushed the system, no change.

All rads have been changed.

I still think that there is a blockage in the pipes at low level, the customer has said that its never worked in the 10years hes lived there but it gets worse year after year, strange
there is evidence of the f/e tank overflowing boiling over maybe? and there was no inhibitor in the system.

I'm stumped, don't know what to do. He wants to suss out whats wrong with the system before he goes ahead with fitting a new boiler (combi) which has always been the plan. I've said the best thing to do is go ahead with the new boiler, do away with the old circuit under the floor downstairs (which is set in cement with no protection) and run a new circuit under the floor upstairs with drops to all downstairs rads.

He still pushing me to try and fix, is my advice the right advice? any help or suggestions greatly appreciated. I try not to sell the most expensive option to customer but hes already spent over £1000 with every thing and it seems hes chucking good money after bad?

Frustrated plumber

 

[SimonH2]

Sounds more like a question for the plumbing section, but to my mind it sounds like you are giving reasonable advice - there comes a point where it just not worth throwing more time (and hence customer's money) at the problem.

However, have you tried some simple "can I get water through" type tests ?

Eg, if you connect a hose from the mains to the flow (disconnect from boiler, take return to a drain), can you get flow round the system ?
Try closing all the valves, then open them one at a time - should allow you to check that each rad individually is capable of a good flow.
If that works, then maybe include the boiler (re-connect it's return, take it's flow to a drain) - not impossible that the boiler is scaled up (especially if it's an old cast iron heat exchanger).

 

[Nick E]

I had a similar problem with an old system last year. I spent enormous amounts of time doing all the obvious things before discovering a very old anti-gravity valve which was almost completely blocked.

A long shot but it had me stumped on the sytem I was trying to fix!