Heating problems

rkisacelticfan

Please help!! I recently built a new house (moved in July 09). I've only recently started consistently using the heating and I'm having some problems. My system is as follows:

Oil burining condensing boiler in the garage.
Stove with back bolier in the sitting room.
All rads have thermostatic valves.
12 rads downstairs
5 rads upstairs
Automatic valves in hotpress allow for zones up and downstairs.
3 coil cylinder in downstairs hotpress (as I've solar panels also)

Problems:
1. 3 of the downstairs rads need to be bled every 3/4 days in order for them to have any sort of heat. At best they get just above luke warm.
2. 1 of the down stairs rads doesn't heat at all and even the hot water feed into the bottom of the rad is luke warm at best
3. One of the upstairs rads is always scaldy hot no matter what the thermostatic valve is at.
4. Condenstation in the attic near the expansion/feeder tank

What I've tried:
1. Shooting the plumber...
2. Turned pump on bolier and stove to level 2 setting. Then left one at level 2 the other at 3 and vice versa but all this did was stopped the rads from heating at all (well after 2 hours of sitting in the cold they hadn't heated)
3. Removed and cleaned affected rads for sludge / grime that may have got in during building.

I've done some research and read alot about balancing and pressure. Could this be the cause? Should I get the plumber to do this? I want anything but to dig up my lovely new floors looking for a leak....

blackbox

It sounds like a job for the plumber - If this is a new build it seems like it was never commissioned (which should have been part of the job).

I had a similar problem to this which the plumber called "pitching" (it may have been his own word!) This was water circulating in the system up the expansion pipe and into the header tank when the pump was running.

I suggest that you go into the attic with the system running to see where the heat/condensation is coming from. Try it with each pump running one at a time and both together.

In my case two systems were sharing a coil in the cylinder but there were two down-feeds. When one of these was closed, the problem was solved. With your 3-coil system they should all be completely independent, so this shouldn't happen (has the plumber combined the expansion pipes?)

This is quite a complex system, especially as your cylinder is downstairs and you will probably need a pump even for the back boiler (little or no natural convection). I expect it will take some trial and error to get it fully balanced.

Hopefully, though, you won't have to pull up any floors...

rkisacelticfan

Last night I just lit the stove and all of the rads heated fine - expect the one downstairs that has no heat whatsoever. Also I chekced the pressure and it is at just under 2.0. The plumber is coming in the morning to have another go!

ccsolar

Hi
Your system needs to be balanced,
3. One of the upstairs rads is always scaldy hot no matter what the thermostatic valve is at.
Start with shutting down this radiator valve until it is all most closed ,
See what effect this has on the other rads.
I don't think you have a problem with "pitching" as the over flow in the tank would point this out.
I recently built a new house (moved in July 09).
Do you not have a warranty from the builder?

Let us know how you get on,

Cc

items

Sound's like system is full of air, never filled properly or commissioned into use.

You'll have to find out where heating fill valves are located, open them all up and start venting one by one. Once system is completely full of water, best balance all rads.

Look for an old thread called, luke warm rad, I listed out how to balance system.

Take one system at a time, do rads and boiler first, fill / vent / balance then go onto stove, if its combined into heating (boiler and rads) run stove separate with boiler off, same again fill / vent / balance. When filling and venting, you can turn boiler on, set at lowest heat, helps move water for filling / venting, same with stove if its possible. Only when everything is full of water, you go onto balancing with heat on.

rkisacelticfan

Thanks for the help guys. The house is a self build that I managed myslef so no main contractor. I owe the plumber about €500 though so I'm not too bad as long as there are no major problems!! I'll try the balancing myself tonight and post my results on Monday - wish me luck!!

rkisacelticfan

So I got up early Saturday morning ready to have a go at balancing the sytem. I turned off the system and made sure it was cold before bleeding all the rads and I discovered more problems:
* Another one of the upstairs rads (its in a storage room that we hardly use) drew a blank when I tried to bleed it - no water, no air, no nothing. So I didn't continue any further with the balancing
* Also my stove (the actual stove body, the sides and back) heats up when i turn on the central heating. it gets scaldy hot and the pump on the stove seems to come on immediuately when I turn on the central heating. My plumber is blaming the pipe stat (whihc is on the hot pipe from the back of the stove) but access is difficult to that.

Please help!!