pumped system pumping over

[eddiebrown424]

Hi all,

I went to look at a job today in which the header tank is full of hot water and overflowing.

There is back boiler and the pipework runs upstairs to the cylinder but i can see no valves. I did not want to take out the fire and told the customer that I would prefer to do some research away from the job. Is there such a system (excuse my naivity) where there are four ports comming off the boiler for primary and secondary circuits. The system is around 30 years old and at this point i did reccommend an upgrade as in my thinking there could be several issues and it may be more financially viable/ sensible to put in a combi although i would like to resolve the problem if possible

I thought that the issue could be,

A blockage---- solution powerflush or cut out the affected pipework
overheat stat on the boiler failing although this did switch on and off when tested.
pump in the wrong position the pipe layout is not something I have encountered before i.e the primary 28mm going straight to the cylinder and returning to the boiler. with the 22 mm secondary pipework not visibly connected i.e. through a motorised valve.
A really long shot.... a split coil although i am sure Central heating water would enter the hot water and not the other way round.

I cannot see a by-pass on the system lthough i assume that if all circuits are connected at the boiler it may not need one. Also I could not see any motorised valves although i only called in as it was a friend and i stupidly thought the problem was going to be the ball valve in the cwst and a quick fix.

any advice really appreciated.

I do have some pictures but most pipework is hidden as is the boiler. I found this and not sure if it helps

https://www.google.co.uk/search?q=p...2eV1xCIbM:&usg=__dUBpzTOWixg8_GNCDJmeNln53-0=

 

[jtsplumbing]

On some of these old systems pump did go on return as cold feed & expansion were took of primary F&R on cylinder as this was a direct line to boiler, some went straight back to boiler

 

[stevetheplumber]

nearly always on the return for this system boiler acts as a negative point so pump doesnt afect the cold feed and vent my guess would still be the boiler stat is letting it all get to hot or the immersion is on as well

 

[jtsplumbing]

If its a Baxi may have a chance of replacement stat, got to remove 2 x BBU in new year (Mysons) nothing available 30 + years old, (Incase hammers is watching ! Ex-Naval estate Tamerton)

 

[lame plumber]

wonderful area seen a few waking up there of a morning in full dress rig trying to get a ride back to their ship................

 

[jtsplumbing]

wonderful area seen a few waking up there of a morning in full dress rig trying to get a ride back to their ship................

All Private now, non of that washing powder signals in windows anymore when hubby away

 

[stevetheplumber]

All Private now, non of that washing powder signals in windows anymore when hubby away

old man out i loved seeing that in the window lol

 

[jtsplumbing]

old man out i loved seeing that in the window lol

What happened to that washing powder ?? can you remember what other ones were

 

[stevetheplumber]

dreft tide omo and daz
we had a couple of blokes who ran a scrap yard down the cali always rotten dirty and they were known as dreft and tide

 

[thompsonbrown]

thanks stevetheplumber. The water is red hot i nearly made a cup of tea whilst I was up there lol.
I will do the tests for a split coil and also check the vent is high enough. Last silly question there has to be a diverter valve doesnt there? I couldnt see one but how else do you only have hot water?.,.,.,., Thanks again Eddie

Eddie

I would say its more likely to be a pump problem than a split coil. as you say your F&E tank is lower than your hot water one.
You wont find any zone valves or diverter valves on a 4 pipe system. 2 pipes for cylinder 2 for rads
pump position and where they have linked in the feed and expansion pipework is more likely to be your problem.

 

[gassafe]

Drain the cwsc & see if the tank stops overflowing, should prove its a split coil?