Heating / Radiators issue

GT60

Hi My boiler has been serviced and my radiators are always warm at the bottom and slightly hotter at the top.
Yet the towel Rad that’s in the Bathroom is always very hot both top and warm bottom
The boiler heatline caprizplus 28a in the upstairs bedroom and the pipe work going to the rads is 15mm but 20mm at the boiler if that makes sense
When I ask the engineer he blames the issue on the 20mm pipe not going to the first rad but being reduced to 15mm after about 2 foot from the boiler
Sorry i want to know why the rads are cold to slightly warm at the bottomvis it like the engineer said?
The TVR's were turned up full by the engineer

sorry about the photos

thanks

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Warwick_Hunt

Do you have a question or are you just sharing it with us?

GT60

Sorry i want to know why the rads are cold to slightly warm at the bottomvis it like the engineer said?
The TVR's were turned up full by the engineer when he serviced the boiler.

G_M

Sludge?

Either remove the rads and clean them, or fush/powerflush.

Or it could be the pump circulating the water is not powerful enough for the extent of the system. Some pumps have 3 setings (low, med, high). If so try turning it up.

PhilE

Check the lockshield valve on the radiators, they might need closing slightly.

Any gurgling noises in the system would mean that air is in there and would prevent a rad from fully heating up.

As others have mentioned, there could be sludge in the system.

Some of my rads can be less hot at the bottom, but not cold. I've never found this to be an issue and only noticed it recently.

If you haven't had this issue before, perhaps the pump needs changing? If the engineer feels that the pump is working correctly and changing the pipes he's pointed out doesn't solve the issue, perhaps an additional pump will solve it.

Ganga

PhilE wrote: »

Check the lockshield valve on the radiators, they might need closing slightly.

Any gurgling noises in the system would mean that air is in there and would prevent a rad from fully heating up.

As others have mentioned, there could be sludge in the system.

Some of my rads can be less hot at the bottom, but not cold. I've never found this to be an issue and only noticed it recently.

If you haven't had this issue before, perhaps the pump needs changing? If the engineer feels that the pump is working correctly and changing the pipes he's pointed out doesn't solve the issue, perhaps an additional pump will solve it.

Or a change of heating engineer!:rotfl:

vacheron

If a heating system is working efficiently there should be a noticeable (and similar) difference in temperature between the top and bottom of all radiators because the water leaving the radiator (from the bottom) should ideally be about 10-15 degrees colder than the hot water entering it (which rises straight to the top due to convection) the heat lost has transferred into your room, so is to be expected.

You can get a quick feel for this simply by (carefully) putting your hands on the in and out pipes of the radiator when the system has been running constantly for at least 15-20 minutes with all TRV's set to maximum.

I the temperature difference feels larger than the other rads then that radiator isn't getting enough water flowing through it (or has a lot of sludge inside it which you can tell if the bottom of the radiator between the valves stays cool while both sides near the valves warm up).

If the in and out temperatures feel almost identical (as may be the case with your towel rails) then those radiators/rails have too much water flowing through them so they are returning water that is too hot to the boiler which could cause issues with the system response time and boiler efficiency.

If the water leaving some rads are too cold and others too hot, then the system could be unbalanced and the lockshield valves on the hot rads should be closed slightly and the cold rads opened up slightly. If this does not result in an improvement you could have a sludge / partial blockage issue.

GT60

Thank you very much for that.

bris

The water comes in the bottom and circulates round the radiator and out the other end. A clean radiator will see even heat all over.


In a sludged up radiator the water will navigate round the sludge that is built up at the bottom, that's why its warm, they need power flushed.

GT60

Thank you every i will check everything you all have said .
I only moved in the House a year half ago so font know the history of the system.
Thanks again