Radiator only gets hot in Summer!!

[Jass]

We have a small radiator in the bathroom which is on the gravity hot water system and only gets warm very slowly and sporadically. You can almost sense the hot water ebbing and flowing in the radiator - beginning to warm up, and then draining away.

I have seen comments in other posts suggesting partial radiator blockage as a likely cause of this kind of problem, but -- the problem only ocurrs in Winter, ie. just when we need the radiator to be hot! In summer, when the hot water system is operating, but the pumped radiator circuit is off, the radiator gets lovely and hot, ie. just when we *don't* want it to!!.

Any expert suggestions as to the cause and the remedy would be very welcome.

Jass.

 

[Newboy]

Your bathroom radiator is plumbed into the hot water circuit - makes your bathroom toasty warm when you have a bath!

Short of re-piping onto the central heating circuit you can't really change it

 

[Jass]

"Newboy",

Thanks for the response. Yes, you are right about the 'lovely' warmth in the bathroom, but this only happens in the Summer months when the pumped radiator circuit is mostly swithed off.

In Winter, when the hot water circuit *and* the pumped circuit are operating, the bathroom radiator just will *not* get anything better than slightly warm - and it takes a long time to get there, meaning the bathroom is stone cold on Winter mornings.

Any suggestions as to the 'seasonal' variation?

Jass.

 

[Nige F]

Listen to an OldBoy Who`s installed gravity circuits........take the rad off and flush it out , as you suspected it`s probably silted up. The pipework configuration MAY be interfering with the grav. circuit when the pump is on , my psychic eye doesn`t work North of Watford. New boy thinks it`s on a secondary circuit , it could be , but also could be off the primaries

 

[Jass]

Thanks for your reply Nige F.

The current spell of warm weather means that the CH pump has not been on at all, and the bathroom (Gravity) radiator is as warm as toast from top to bottom. Hence I do not think that silting is a signifant cause of the problem.

I am interested by your comments regarding the pipework configuration. What should I be looking for; and what could I do about it?

(If it gives any clues, the system was originally solid fuel driven, and the solid fuel unit has been simply switched for a gas back boiler with no other amendments to the system).

Thanks in advance.

Jass.

 

[Heating Boy]

Would prehaps upgrading the system to a fully pumped system might be the best bet to this chap?

Just a thought.

 

[Nige F]

Ah Solid Fuel ...then it (bathroom rad) would have been incorporated as a deliberate feature to act as a "Heat Leak" because solid fuel is virtually uncontrollable .......so most likely off the primary circuit ....OK. look @ vent pipe from flow going into side of Hot Cylinder.follow it up thru ceiling and into attic .....before it goes up+over the small cistern it should have a branch ..this then should go to the rad.and it should be 22mm/3quarter pipe .....a valve fitted to this and shut in the Summer will stop the circuit of water ........there may not be rad valves on the rad....I wouldn`t have fitted them ,and would have told householder about the heat leak ..........AS to making it work when you want it to Only way would be to look @ it`s layout and make suggestions ...HtH

 

[Jass]

Nige F,

Thanks for that.

I think that if the solution is in the layout of the pipework, I had better try and find 'someone who knows' to have look at it.

Thanks again for the suggestions.

Jass.

 

[Nige F]

50yrs. plus would put us in the age group who started on grav. hot water and then covered fully pumped

 

[Jass]

Nige F,

50 years plumbing experience *and* nearly 3000 posts to the forum! You should be writing a book!

Moving to a fully pumped system has now been mentioned by you as well as 'Heating'Boy'. Do you think this is the way I should be going?
(Currently Pumped CH + Gravity Water, both from a back boiler).

Thanks

Jass.

 

[ChrisR]

Intrigued to know why it shouldn't warm up in the Winter. Nowhere NEAR NigeF's age and only been plumbing 5 minutes. I don't actually know anything, I just copy other people's posts.

Just wonder if there's something daft like an anti-gravity valve somewhere which is shutting when the pump's on. (Lumpy brass thing in the pipe with no handle etc)

But yes, a change to fully pumped would be a good thing.