Potterton Back Boiler has hot radiators but no hot water

[esky365]

The entire system has been fine for almost three years since we moved in. I have never touched it other than bleeding the radiators. The radiators are perfectly hot, the boiler springs into life and rarely locks out.

Yet we have no hot water. It is sort of tepid. It started about a week ago and the temperature of the water has just disappeared.

Both of the motor valves are working, and the little radiator nearest the hot water tank is getting very hot when the back boiler is on, even when the radiators are turned off.

We have done nothing to any of the central heating system to upset it.

I would be very grateful for any advice.

thanks for your help.

 

[plumbingservices]

Sounds like motor valve to your hot water isn`t working properly,there`s a little lever at one end,pull it gently across, you can lock it into position see if water heats up.

 

[esky365]

Sounds like motor valve to your hot water isn`t working properly,there`s a little lever at one end,pull it gently across, you can lock it into position see if water heats up.

I can see the motor valves working, the switch moves across when I press "on" the controls on the hot water.

There are three pipes on the hot water tank. The lowest is cold, the one above that is scalding hot, just where it enters the tank, that is just past the motor valve, and the one at the top of the tank is tepid.

Coming off the "hot" pipe is a short vertical pipe with a small canister on top. It says in french "purgeur floteur" which according to google is a steam trap.

A bit like this one http://www.outiz.fr/medias/sys_mast...laiton-brosse-flotteur-1323003-00218-01-L.jpg

 

[Dan Robinson]

Blocked cold feed.

 

[esky365]

Blocked cold feed.

How can that be fixed?

 

[Dan Robinson]

Search the forum... been discussed almost as much as "what new boiler".

Not hard to fix when the offending section of pipe work has been found.

 

[plumbingservices]

Dan, Seeing as though the f and e is only to top up heating and hot water is maintained thru heating coil how would blocked cold feed affect hot water wouldn`t it affect his heating? Only asking cos I can`t get me head around it being cold feed blockage by the way. Poster, bleed one of your radiators, probably one with air in somewhere, if they refill you don`t have a blocked cold feed.

 

[Steelmasons]

Dan, Seeing as though the f and e is only to top up heating and hot water is maintained thru heating coil how would blocked cold feed affect hot water wouldn`t it affect his heating? Only asking cos I can`t get me head around it being cold feed blockage by the way. Poster, bleed one of your radiators, probably one with air in somewhere, if they refill you don`t have a blocked cold feed.

So are you saying the water in the cylinder coil/annular is not from the same 'source" that of the central heating water???

 

[plumbingservices]

So are you saying the water in the cylinder coil/annular is not from the same 'source" that of the central heating water???

No, I`m saying that the hot water cylinder is heated via the coil and transferred through the coil to the hot water cylinder, the cylinder is fed via a header tank independantly from the heating or Feed and expansion tank, a blocked cold feed is a blockage from the cold feed from the tank in loft feeding the central heating system only usually evident by cold radiators that do not vent any water when bled.

How would a blocked cold feed which tops up central heating circuit possibly influence the hot water system? My understanding is this is an S plan system. What system do you think this is Steelmasons? Take time to look it up. Do you think that the water in the cylinder is the same flowing through the radiators steelmasons ? Do you know what a blocked cold feed means?

 

[Phill Peck]

This is the problem with this industry u get people like this Steelmason who get sick of working in an office and think they can take on the world of plumbing and heating.

Wouldn't know a blocked cold feed if it hit him in the face.

OP probably some aliens fell in the header tank check for nearby crop circles or abandoned telcos trollies in the garden

 

[Steelmasons]

How would a blocked cold feed which tops up central heating circuit possibly influence the hot water system? My understanding is this is an S plan system. What system do you think this is Steelmasons? Take time to look it up. Do you think that the water in the cylinder is the same flowing through the radiators steelmasons ? Do you know what a blocked cold feed means?

So you've not known a cylinder coil to run dry due to blocked feed and expansion pipe? (also referred to as a COLD feed) , also if cylinder happens to be in loft space radiators could still have water dripping from bleed nipple when opened.

 

[plumbingservices]

Clutchin at sraws mate, open vented cylinder in loft? Where`s header tank go? coil ran dry ? cylinder in loft has nothing to do with heating system, blocked feed and expansion pipe refers to heating system, not hot water cylinder, please, stop it now, it`s beyond cringeworthy.

 

[Steelmasons]

Laughing stock..

 

[plumbingservices]

You certainly are....

 

[esky365]

Dan, Seeing as though the f and e is only to top up heating and hot water is maintained thru heating coil how would blocked cold feed affect hot water wouldn`t it affect his heating? Only asking cos I can`t get me head around it being cold feed blockage by the way. Poster, bleed one of your radiators, probably one with air in somewhere, if they refill you don`t have a blocked cold feed.

I have bled the rads, and they did top up.



Incidentally, I am not on here so I can bodge it all back together again, I am on here so I can get my head round this stuff when the heating engineer calls.

I spoke to him on the phone before coming here, and he reckoned if it wasn't the motor valve, and it isn't, then I need a new boiler.