New rads not heating- Boiler pump position?

[Richiejol]

Hi
I've just had a bit of work done in the house where we knocked down the wall between the kitchen and dining room. This wall had radiators either side. Two new radiators have been installed in the new open plan area. When the plumber came to fit the rads and balance the system he was unable to get heat to the 2 new radiators. He believes the boiler pump is fitted on the wrong side of the T-Piece shown in the picture below which makes sense if the other 2 pipes coming off the T-piece are going to the rest of the system. However I can't understand how there wasn't an issue before?

 

[Harvest Fields]

Has he piped them in correctly? Do the get warm at all?

 

[Richiejol]

Yes the piping is fine. When I turn down the rads on the rest of the system to almost closed one of the new radiators is heating and the other one is only getting slightly warm. Does the pump position look correct?

 

[Harvest Fields]

Yes the piping is fine. When I turn down the rads on the rest of the system to almost closed one of the new radiators is heating and the other one is only getting slightly warm. Does the pump position look correct?

What size is the pipework and each radiator?

 

[Richiejol]

The pipe sizes are the standard 15mm. I dont have the exact sizes for the rads but the one that I can get heat to is about 800mm long and closer to the boiler. The other larger one is around 1.5M and further away.

 

[John.g]

Is the pump discharge just above the pump cooler than the flow from the boiler?, just wondering if you are getting some kind of reversed circulation.

 

[Sharp Point]

Yes the piping is fine. When I turn down the rads on the rest of the system to almost closed one of the new radiators is heating and the other one is only getting slightly warm. Does the pump position look correct?

Without sounding RUDE😀... how do you know the piping is fine?

 

[Richiejol]

Without sounding RUDE😀... how do you know the piping is fine?

Fair point. I can only presume the piping is correct as I cant see where they made the new connections but I presume its ok if heat going to one and the other is warming slightly. But my main concern would be the fact they want to change the pipe work after the boiler so that the T-piece circled is effectively after the pump. Would this be normal?

 

[Ben-gee]

It absolutely sounds like a balancing issue, surely?

 

[Stu-B]

What type of rads are they? Some of these new designer column fancy pants rads can only be piped a certain way as per instructions.

 

[John.g]

Fair point. I can only presume the piping is correct as I cant see where they made the new connections but I presume its ok if heat going to one and the other is warming slightly. But my main concern would be the fact they want to change the pipe work after the boiler so that the T-piece circled is effectively after the pump. Would this be normal?

"T-piece circled is effectively after the pump. Would this be normal?"
Cant see how you see it this way, the pump is pumping from the boiler (flow) and that T piece is on the suction to the pump and should be on the discharge side?, the only way I can see this working is that the pump is sucking from the (or some) rad(s) and mixing this cooler water with the hot water from the boiler, it can't be sending water out through this T piece.

Sorry misread your post, yes I think that T should be on the pump outlet

 

[Gasmk1]

is that tee below the pump the old expansion pipeas it looks like a combined coldfeed and expansion. i know its got a blow off but it was a conversion at some point

 

[Richiejol]

is that tee below the pump the old expansion pipeas it looks like a combined coldfeed and expansion. i know its got a blow off but it was a conversion at some point

Yea think you might be right I traced the pipes from the tank and they go from the attic straight down the wall of the hotpress and under the floorboards at a point which is about 12 feet directly perpendicular from the pipe work in the picture. That explains why there wasnt an issue before the new rads were fitted. I havent heard back from the plumber so I begining to think he just didnt want to balance the system.

 

[DAVE01]

Hello i do not no what boiler you have but it would be far better if you made it a closed system will work better for sure If what you are saying if its a combined cold feed and expansion it is really called close coupled cold feed and expansion what can become a problem when you close couple a boiler is you take expansion off as pipe rises to attic this not correct as the first thing that will happen is it will expand up the least line of restince only way to do it correct is elbow first then tee on the run on the flow then another tee for cold fill but invert tee this can be no more that 6 inches between tee for expansion and cold feed but make sure you turn the tee for cold feed down this what i mean by invert the tee expansion and cold feed must be 22mm the reason why not many Plumbers use a combined cold feed and expansion you can be looking at 6 lengths of 22 copper to bring pipes to attic plust the cost ? other option is to take pump from were it is you have the two pipes going to cylinder and use the combined cold feed and expansion up at hot press have along with pump and pump will pump out of boiler . But i think you would be mad make it a closed system just were the first tee is put a safety vale there with a gauge on the return but a pressure vessel 18 lt but a filter on boiler upstairs put a Auto vent bushed down to 15mm on expansion this is top pipe on return put a filling loop but connect this to mains water you will not actavate the flow switch on boiler most boiler you need a bar pressure so connect this to mains water through filling loop and it would be a good idea to put a scale filter to stop boiler from scaling up and a pressure reducing valve reason i say use a pressure reducing valve is you have now made heating system from open to closed so any small leeks in a open system would be taken up by tank in attic this is not case in a closed system if you loose pressure boiler boiler will not fire if it goes own below 1bar best of look

 

[John.g]

is that tee below the pump the old expansion pipeas it looks like a combined coldfeed and expansion. i know its got a blow off but it was a conversion at some point

Here is my system, installed from new, it must be one of the shortest combined vent and cold feed systems around.

 

[DAVE01]

No this pipe work arrangement is no longer accepted its old full stop we used this method about 40 years ago as a matter of fact any system like this we disregard and re pipe The safety valve is in wrong spot put it on the 22x15x22mm 15 connection than just re pipe it back to the pipe going out wall do away with tank in roof space you have a mains connections use this for cold feed to heating to heating use a filling loop oh make sure the safety valve you use has a gauge same thing with filling loop this just means you are not runing up and down stairs watching gauge worst case if you put too much pressure on heating it will lift seating on safety valve and can be a devil to re seat dirt can get under seat and just leek On the return on boiler put a 22x22 x22 mm tee pipe this to a 18 lt pressure vessel . On that 22 mm pipe comeing off flow and going to you combined cold feed and expansion reduce this from 22mm to 15 mm with a reducer from 22mm to 15 mm put a automatic Air vent this is just to vent cyclinder On the return you might have to put a 22mm gate valve this is just to trottle down cyclinder what can happen cylinder can rob all the heat use this 22mm gate valve buy useing it to trottle down cylinder To make your heating a bit friendly on your pocket use a room stat ideal place for stat is in hall if you have no controls on your boiler the boiler just cycles on boiler stat and the boiler does not know when the house is hot enough if you use a room stat just set stat at 18 degrees than put it up a notch until you are happy with heat Another method to use is use TRVs in bed rooms ets if useing TRVs make sure you close all doors pointless haveing These valves and all doors left open you might as well have nothing . if you you pressurize the heating what can happen is you will notice a drop in gauge if the pressure does drop use a Pressure reducing valve on Mains water going into the Return just keep this set to a bar Pressure and use a lime scale bulb to stop boiler scaleing up heat exchanger All Boilers need a Permanent Live the idea of Permanent live is 1 it gives you pump over Run and takes latent heat out of heat exchanger 2 It gives you frost protection only thing is if you have it in a place were boiler were say boiler is not say in a garage and its not insalated the boiler will fire if you get a heavey frost but it will not knock off To get around this wire a external Frost stat with a Strap on pipe stat on return set pipe stat to 25 degrees this will sort this out Hope this will help Best of luck

 

[N plumber]

Hi

The Flow vent pipe and cold feed pipe shouldn't be more than 150 mm. Due to more gap between them , the pump sucking cold water more. If your new radiator has only cold water flowing then that means it's definitely pump location and gap between those cold and flow vent pipe.

All the best

 

[DAVE01]

Hi

The Flow vent pipe and cold feed pipe shouldn't be more than 150 mm. Due to more gap between them , the pump sucking cold water more. If your new radiator has only cold water flowing then that means it's definitely pump location and gap between those cold and flow vent pipe.

All the best

Yes i think it would be far better if it was made into a closed system far better job no problems with air i do not think a open system is used much well over here anyway not sure about UK Any way there are a lot of plumbers that do not close couple Feed and Vent they just pipe it as it is its a case of hope for the best well thats the case in Ireland But if you look at any the tec manuals if you use a open system it has to be close coupled if you fail to do it as to there spec it is a get out for the most of the makers of the different boilers on the market . Over here if you get a new replacement boiler the installers do not even give a room stat need i say more Only problem as i see it even if you use a close coupled method you will not get a get a 1Bar pressure at boiler if you do not get that boiler will not fire the majority of boilers use pressure switches in sted of float switches but i stand corrected this could be all sorted out with the new breed of boilers I know many a time i had to use a test bucket to push up pressure on boiler to a 1bar on a open system All the best