steam from elson tank

[duncanbru]

elson located above potterton kingfisher in airing cupboard, when the boiler has been on for over an hour, steam is emiting from the tank and filling the room, pump is running, rads heat up, thermister and over heat stat have been checked!

any sugestions?

many thanks duncan

 

[sonray ltd]

can only be getting to hot

 

[duncanbru]

any sugestions as to why? it's over heating? no immersion fitted, boiler stat working, pump running, i can't work out why it is over heating!

 

[sonray ltd]

whats the temp like out of the taps ?
providing it is filling and working ok.

 

[duncanbru]

temp high and flow good, tank feed working fine

 

[sonray ltd]

its not got a stat on the tank.
yrs since i've seen one on a boiler, only immersion ones.

 

[duncanbru]

no tank stat fitted! not sure if it is possible to retro fit one on an elson? if so this would rectify the problem but still dose not determin the cause, it is an old ex council property that has just been bought and new owners have this problem, so no history of the system however the thermister did look very new so wonder if the former owner was having simaler problems

 

[sonray ltd]

as you say has the problem been there before.
no tank stat it just relying on the boiler stat.

 

[duncanbru]

yep just relying on the boiler stat, which is working perfectaly! no zone valves fitted, just gravity fed hw and pumped ch circuit so not realy much to go wrong! its got me bamboozled!!! asked loads of local coliuges and every one says hmm strange, scratches there head and walks away!! bet it's something simple but just cant work it out!

 

[sonray ltd]

so its acting like a standard gravity indirect cylinder with no stat like the old 70's installs. and they never done that. is strange.

nothing coming out the overflow.

 

[duncanbru]

yep thats exactly what its like! and nope there's nothing coming from over flow. ran boiler on max for 50 min on wed night, small spurt from expantion pipe about 5 min after it fired up bit then nothing. ran till the boiller was virtually glowing, couldn't touch the ch pipework or primaries dhw was warm but not too hot, turned the boiler stat down to low and left ( 3rd visit ) call last night saying heating had been on for 2h and the steam was once again rollong out of the tank and accross the cieling in the bedroom!

 

[sonray ltd]

no chance of a slight blockage or resriction in the expansion pipe.

 

[duncanbru]

possibul but unlikely, wouldn't of thought it would lead to the overheating problem tho, as no hw returning to the tank!