Heating problem

9"solids

Hi folks,
maybe ye could shed some light on my heating problem.

3 bed semi - oil burner and pump working fine.

When i put the heat on - the rads downstairs get piping hot.
Upstairs the hot supply comes up thru the back of the hot press and divides in two.
1st supply - goes to main bedroom and heats rad fine -copper
2nd supply - goes to 2 other bedrooms and bathroom but does not heat rads at all.
The pipe - qualpex- from the 2nd supply heats fine when I reach at the back of the hot press but obvioulsy doesn't get to the 3 other rads.

Q - is it possible that there is a blockage on the 2nd supply between hot press junction and the rads ?
Q - Is there a way of flushing out the line to get rid of any dirt.?

just to add --- all rads have been bled and the system supply tank is working fine in the attic - and all rads are turned on !!

When I emptied the system last year to do some work -it worked fine for a few weeks and then started to go bad again --- need to get this fixed asap.

thx in advance

rooferPete

Hi,

You have two supplies in the hot press, one usually serves the cylinder while the other serves the radiators, I noticed you didn't mention a supply to the cylinder.

Sometimes there is a gate valve on the flow to the cylinder to regulate the amount of hot water serving the cylinder, it could be that the cylinder is taking all of the hot water and returning it to the boiler for re-heating.

As the second supply is in Qualpex it can happen that the pipe was bent at a tight angle restricting the flow of the water, naturally the flow and return will take the line of least resistance and disregard the Qualpex section.

That said the fact that the rads are full of water could mean the system needs to be balanced you could try switching off the radiator in the main bedroom to see if the other rads heat up.

.

Lex Luthor

I'd have to agree with Pete...possible kinked qualpex pipe or system needs balancing.
We got 2 extra rooms put on our place 2 yrs ago with qualpex. Found that they were the last 2 rads in the system and were not heating up.
Turned out the other rads were taking all the heat and balancing the system cured it. I referenced this web site and did the job over the weekend.

http://www.diydata.com/projects/centralheating/balancing/balancing.htm

9"solids

thx for the replies

I do have a cylinder valve and even when this turned off (no hot water to the cylinder) and the downstairs and main bedroom rads are off - it still does heat the 3 other upstairs rads.

I will have a root arount this afternoon and see if there is anything stopping the flow.
I might drain the system and flush mains water through the 3 problem rads.

update later,

kiss103

Try this

Turn all your downstairs radiators and emersion loop off, then run system for about 15 minutes , check if any heat is going to non qualplex fed radiators , if not then problem with feed pipes or an awful lot of air

Turn off heat and pump and bleed radiators ( don't ever try and bleed with pump running as this can also draw air into system !!! ) , if there is heat in these radiators then start balancing system as per above post,
Another problem could that there is a feed pipe which is higher than rads , this could then be airlocked and if this is the case a bleed valve will need to be fitted to this .

9"solids

Ok.
over the last while I did the following.

Turned off the valves on the 3 problem rads.
Completely emptied the system of water from a drain plug near the pump.

Took up a few floorboards where there is a junction for the 3 problems rads.
Opened this junction (with a basin underneath) and the opened the value of each prob rad in turn.
All the water is flowing ok and clean -which implys no dirt blockage !!

So after this exercise I would be inclined to think that this problem was due to an air block between the junction to the 3 rads and the rads themselves --- how do I fix this !!!

just read that I could reverse fill the system from my drain valve and push the water up instead od down from the header tank ??
any info ??

9"solids

3 rads still not heating -- any ideas ??

It's as if the hot water just does not want to go to the 3 rads even with all other rads off --- getting a bit miffed now !!!

would making it a sealed system work ????

thx

yop

Could there be a problem with the circulating pump not pushing the hot water to the rads?

Lex Luthor

yop wrote:

Could there be a problem with the circulating pump not pushing the hot water to the rads?

some of these circulating pumps are adjustable...when we went from 13 to 15 rads, I turned it to the next position up.
In turn, I balanced the system aswell and no problems since....

kiss103

Have you a bypass valve in your boiler room , and if so is this open or shut , it could be that there is one and you are losing pressure through this so the system can't get the heat to final rads ?