Hi all, ABout two years ago I installed with my plumber friend a HEP (22mm) based system with a system boiler and megaflow. The heating recently about 2 years after installation I think is different. The rads downstairs which all have 3m drops down from the ceiling to the rad in 15mm copper seem extra cold at the bottom. When the heating is on the rads are superhot at the top where you cant really hold it but I can hold the locksheild pipe going back up to the ceiling and the bottom 50% of the rad is quite cool and easy to touch. The rads are all K2. I dont believe it was like this before any advice what it might be?all downstairs rads all are K2 and 1200mm wide minimum. The baxi system boiler is reading nearer 2bar pressure, When i have decorated each room i have removed the rad. As eacg down stairs rad is fed from the ceiling down they all have 3m long drops (tall ceilings) and is all in 15mm copper from the ceiling down and 22mm from the boiler. I have experienced air lock in the down pipes when reconnecting the rad. to help resolve this I switched all TRV's off and put the one rad on full blast and it heats up evenly. Could the return pipe be airlocked?.... Any advice? should I drain down and refill I have alwasy topped up the inhibitor?
Rads on new system hot at top cold at bottom need advice
- Thread starter activeman57
- Start date
Sponsored Links
If the downstairs rads get hot all over when upstairs rads are turned off, poss balancing problem. Were the rads balanced?
See FAQs for more details -
//www.diynot.com/wiki/plumbing:faq:faq2
See FAQs for more details -
//www.diynot.com/wiki/plumbing:faq:faq2
hi there thanks for the quick reply...
The upstairs rads all seem to be fine. Apologies I might not been so clear. My system boiler is in three zones, heating up, heating down and hot water. Upstairs seems to be fine, just issue with down stairs rads. I have 22mm hep going through the middle of the house the flow and return. The pipes to each rad is t'd in and reduces down to 15mm just above the ceiling, the 2.8m long coper pipe runs down the wall and connects on the rad the return does the same but back up the wall. The central 22mm flow and return are with the maxium lenght before an extra pump is required. I have put plenty of inhibator and the rads are all new stelrad softline, except for two which were washed out by a hose before reusing. I have however removed one rad at a time whilst decorating the room and once or twice air locked the flow pipe as you could hear the air trickling down the copper run! I wonder if the air has moved and is some how in the return pipe and this might slow the water circulation up? I am guessing a but tho. Switch all the trv's off except one forces that rad to equally heat, maybe i should do this. In answer to your question the system has not been balanced and i have openned all the lockshields maximum when replacing the rad.... is this wrong?
The upstairs rads all seem to be fine. Apologies I might not been so clear. My system boiler is in three zones, heating up, heating down and hot water. Upstairs seems to be fine, just issue with down stairs rads. I have 22mm hep going through the middle of the house the flow and return. The pipes to each rad is t'd in and reduces down to 15mm just above the ceiling, the 2.8m long coper pipe runs down the wall and connects on the rad the return does the same but back up the wall. The central 22mm flow and return are with the maxium lenght before an extra pump is required. I have put plenty of inhibator and the rads are all new stelrad softline, except for two which were washed out by a hose before reusing. I have however removed one rad at a time whilst decorating the room and once or twice air locked the flow pipe as you could hear the air trickling down the copper run! I wonder if the air has moved and is some how in the return pipe and this might slow the water circulation up? I am guessing a but tho. Switch all the trv's off except one forces that rad to equally heat, maybe i should do this. In answer to your question the system has not been balanced and i have openned all the lockshields maximum when replacing the rad.... is this wrong?
A system like yours would need balancing, and your symptoms of rads cold at bottom, especially downstairs is often a symptom of unbalanced system.
Is the problem happening when both zones are on (up and downstairs)? What are downstairs rads like when upstairs is off? Does turning on hw affect the situation?
Is the problem happening when both zones are on (up and downstairs)? What are downstairs rads like when upstairs is off? Does turning on hw affect the situation?
Sponsored Links
A system like yours would need balancing, and your symptoms of rads cold at bottom, especially downstairs is often a symptom of unbalanced system.
ok i have one more rad to fit back after a bit of plaster and will get it balanced properly.
Is the problem happening when both zones are on (up and downstairs)? What are downstairs rads like when upstairs is off? Does turning on hw affect the situation?
the HW is done by a storage tank megaflow i think is a phase a mains pressue hw system 300ltr. This heats up in the morning and evening for about an hour or two so doesnt effect the heating and it is seperatly zoned we have never noticed this effect the heating the Baxi system boiler is wickly quick.
thanks for the advice i will update this link when I have done the balancing toward the end of the month! Cheers for the advice.
Read more: //www.diynot.com/forums/plumbi...tom-need-advice.360981/#2730516#ixzz2PWm9KfTd
ok i have one more rad to fit back after a bit of plaster and will get it balanced properly.
Is the problem happening when both zones are on (up and downstairs)? What are downstairs rads like when upstairs is off? Does turning on hw affect the situation?
the HW is done by a storage tank megaflow i think is a phase a mains pressue hw system 300ltr. This heats up in the morning and evening for about an hour or two so doesnt effect the heating and it is seperatly zoned we have never noticed this effect the heating the Baxi system boiler is wickly quick.
thanks for the advice i will update this link when I have done the balancing toward the end of the month! Cheers for the advice.
Read more: //www.diynot.com/forums/plumbi...tom-need-advice.360981/#2730516#ixzz2PWm9KfTd
DIYnot Local
Staff member
If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.
Select the supplier or trade you require, enter your location to begin your search.
Are you a trade or supplier? You can create your listing free at DIYnot Local
