Central Heating Overhaul...

GreeBo

Hey all,
Im in my new house about 9 months now and starting to feel the cold.
Im already looking at insulation options and have ordered the double glazing but I know there are issues with the central heating and Im looking for some pointers on where to start.

Its gas (piped) to rads and the cylinder in the hot press upstairs.

The problems are:
1) As far as I can see its ignoring the room thermostat, I can change to to 6 or 30 degrees and it makes no difference to the boiler turning on or off
2) There is a motorised valve hanging of its bracket, it also does not appear to be responding to whatever is sending it signals (the cylinder I presume?)
3) The valve seems to be in the open position the whole time, I guess this means whenever I have heating on I am making hot water.
4) the boiler turns on an off as if its reacting to something, but I have no clue what it is, as I said it doesnt seem to be the room thermostat.
5) it has a crappy old "pin" timer for the heating but I have a replacement that will do the heat 5/7 day and the water 5/7 day in the one unit. Wiring it is my issue
I also have some thermo rad valves that I want to install (kitchen for example, and want to move the room thermo to the sitting room and not the hall (who lives in the hall!?!)
6) the boiler is I guess ~15 years old, same as the house, it has been inspected and was just cleaned and nothing else said/done.

This all stems from the fact that its bloody cold lately and also Bord Gais dropped in a leaflet offering a free survey leading to an overhaul of whats required for the whole system.
Im guessing they will reccommend a condensing boiler and digital thermometers and timers.


Sorry for the long post but I dont know where to begin on this one and am looking for any advice, even if its "call a plumber" or "call an electrician"
In fact, which would I need, seems like both to me!

Thx again.

rooferPete

Hi Greebo,

Based on your other question and description of the wind your heating system could be confused, you are heating water to go to radiators that may be losing a lot of the heat as it travels under the floor upstairs.

By all means upgrade the system, it looks like it needs a little help, from your description the thermostat on the boiler is controlling the temperature of the system.

Maybe not all bad if the pipes are subject to icy winds.

.

GreeBo

Cheers as always Pete.
I think I'll lift a few tiles this weekend to try and get a general impression of whats going on under the roof, even if I can block it with some timber for the moment it will help!

Would it be a plumber or an electrician I would need or could I do most myself?
(I'm handy enough and have a very handy father!)

Thx again.

Alun

I appear to have a similar system in my house (<10 years old). The boiler appears to turn itself on and off all on it's own, without regard to the room thermostat which only seems to control a motorized valve that switches the hot water flow from the hot water tank to the radiators. Which means that in order to have heating I have to be heating a hot water tank that I don't always need. Speaking to other people on the estate, they don't seem to be able to see what's wrong with this, but to me it seems positively antideluvian having moved here recently from Holland where things appear to be a little more advanced than here.

So, is this a "normal" setup in Ireland, or is there something wrong with the way it's working?

Dades

Alun wrote:

in order to have heating I have to be heating a hot water tank that I don't always need.

So, is this a "normal" setup in Ireland, or is there something wrong with the way it's working?

I have this too. Do the radiators not get their water from the tank? As in the tank feeds the bath/sink but also the rads? I haven't a clue but am in here as I need to get to grips with my own heating system!

I also have that racket in the attic when the loo is flushed, and a constant bubbling all night long.

Alun

The Atheist wrote:

I have this too. Do the radiators not get their water from the tank? As in the tank feeds the bath/sink but also the rads?

No. The hot water produced by the boiler is pumped through a heating coil that sits inside the hot water tank ... that much I do know. The motorized valve diverts that water flow to either the radiators or the tank as necessary.

I'm seriously considering having the whole shebang ripped out and replaced with something from this century like I had before (in the last century!)

Dades

Alun wrote:

No. The hot water produced by the boiler is pumped through a heating coil that sits inside the hot water tank ... that much I do know. The motorized valve diverts that water flow to either the radiators or the tank as necessary.

Ah so the problem is water is being heated to fill both the radiators and the tank, when only the rad water is required...

*solutionless*

pipers

Get a good plumber in, sound like it needs someone who knows what there at to survey the work and then give a quote to remedy what work is required.

regarding the noise in the attic replace the ballcock with an equilibruim type.

Alun

pipers wrote:

Get a good plumber in, sound like it needs someone who knows what there at to survey the work and then give a quote to remedy what work is required.

Thing is, everybody on our estate's system seems to work the same way, i.e. no heating without also heating hot water, so I assumed that that behaviour was "by design", rather than being a fault of some kind that needed fixing. That's why I was asking if this was normal or not.

GreeBo

Alun wrote:

No. The hot water produced by the boiler is pumped through a heating coil that sits inside the hot water tank ... that much I do know. The motorized valve diverts that water flow to either the radiators or the tank as necessary.

AFAIK the heating will always heat the water until the thermo on the cylinder closes.
If you just want water u can use the emersion (just dont forget to turn it off :eek: )
I dont see too much of a problem with getting "free" hot water when the rads are on, it doesnt make much difference as the rads are getting it aswell and the water will stay hot for about 12 hours in a properly lined cylinder. i.e. it should be off most of the time (depending on your thermo setting)

GreeBo

Alun wrote:

Thing is, everybody on our estate's system seems to work the same way, i.e. no heating without also heating hot water, so I assumed that that behaviour was "by design", rather than being a fault of some kind that needed fixing. That's why I was asking if this was normal or not.

I think that reply was directed at me....

I think your situation is pretty normal (well the water and heating part anyway)
You might have a dodgy thermostat if the boiler keeps going on and off when the house is still cold.

Alun

GreeBo wrote:

AFAIK the heating will always heat the water until the thermo on the cylinder closes.
If you just want water u can use the emersion (just dont forget to turn it off :eek: )
I dont see too much of a problem with getting "free" hot water when the rads are on, it doesnt make much difference as the rads are getting it aswell and the water will stay hot for about 12 hours in a properly lined cylinder. i.e. it should be off most of the time (depending on your thermo setting)

I don't think I have a thermostat on my cylinder, only a temperature control on the boiler. And as far as I can see regarding the valve, it's an either/or situation with the radiators and tank, they're not being fed at the same time. So what's confusing me is when the hot water tank is all up to temperature, the boiler is not firing and the thermostat is "on" ... what is heating the water going through the rads?

I mean, is it really that difficult to design a system that both heats a house and heats hot water with thermostats and timing that are independent of each other (with one taking precedence over the other)? (Like the ones I've had in other countries for the past 20+ years!)

Alun

GreeBo wrote:

I think that reply was directed at me....

I think your situation is pretty normal (well the water and heating part anyway)
You might have a dodgy thermostat if the boiler keeps going on and off when the house is still cold.

But there's no connection between the room thermostat and the boiler at all (I've checked!) which is what's confusing me. It's just wired to this solenoid valve that diverts water from the tank to the rads.

JamesM

Alun wrote:

Thing is, everybody on our estate's system seems to work the same way, i.e. no heating without also heating hot water, so I assumed that that behaviour was "by design", rather than being a fault of some kind that needed fixing. That's why I was asking if this was normal or not.

The basic central heating system fitted in Ireland for the past 30 + years is as follows:
When heat is switched on, boiler heats water (in boiler) to a certain temperature governed by a thermostat fitted to the boiler. At the same time a water pump circulates the water to a coil in the hot water cylinder and also to the radiators. Variations of this include a room stat which controls either the water pump or a motorised valve. These will usually control the water flow to all the radiators, when heat is called for in the area where the room stat is fitted. This is not very efficient as the room stats are often fitted in halls or rooms that get heat from the sun, or have even been fitted above rads.
Other variations include stats and motorised valves controlling many zones and also the feed to the hot water cylinder. Sometimes thermostatic valves were fitted.
Nowadays systems have much more sophisticated control systems - but really only in the last 10 years.
Jim.

Alun

When heat is switched on, boiler heats water (in boiler) to a certain temperature governed by a thermostat fitted to the boiler.

So effectively the boiler is occasionally firing up to maintain the temperature of the water in the cylinder coil / radiator loop even if it isn't required, either by the hot water tank or the radiators? That's crazy, if it's true!

JamesM

Alun wrote:

So effectively the boiler is occasionally firing up to maintain the temperature of the water in the cylinder coil / radiator loop even if it isn't required, either by the hot water tank or the radiators? That's crazy, if it's true!

Yes, once the timeswitch is in the on position, the temperature in the boiler rises to, and is maintained at, whatever temperature you have the boiler stat set to.
Then whichever zone calls for heat gets hot water to that zone immediately (rads, cylinder coil etc). There would be too much of a time delay, if the boiler had to heat up every time a zone thermostat called for heat. For example, A room cools down - the room stat calls for heat - the boiler starts up from cold - 15 (or more) minutes later the rad reaches a reasonable temperature - it starts to heat the room ( which has dropped another few degrees from the desired temp) - the room finally reaches the desired temp - the boiler switches off - 1/2 hour later the room has cooled down - the stat calls...................
Once the boiler maintains its temp, the rads get heat as soon as the room stat calls for it and there is very little variation in the room temp.
A modern gas boiler may reach the desired temp quickly, but not an oil boiler. Certainly not with the boilers we have had for the past 40 years.
Jim.

Alun

Hmmm ... I'll take your word for it, but my experience of gas CH boilers in the past (admittedly not in the UK or Ireland) has been that if there is no demand for heating or hot water (these have all been combi boilers BTW) they essentially sit there doing absolutely nothing except very, very occasionally firing up for short periods to maintain the temperature in the small buffer tank. Wind the room thermostat up and they'll fire up, wind it back down they'll stop.

Additionally with my setup, there appears to be no connection between room thermostat and boiler, i.e. I can wind the room thermostat temperature up and down like a yoyo and nothing will happen at the boiler end. Also, if I have the controller programmed for CH only nothing happens ... no heating, nothing, unless I also happen to have the HW programmed for the same time period. So there's no "demand" coming from anywhere as far as I can see, and everything seems to be driven by the boiler thermostat. I still find it all quite bizarre, I must admit.

JamesM

Alun wrote:

Additionally with my setup, there appears to be no connection between room thermostat and boiler, i.e. I can wind the room thermostat temperature up and down like a yoyo and nothing will happen at the boiler end. Also, if I have the controller programmed for CH only nothing happens ... no heating, nothing, unless I also happen to have the HW programmed for the same time period. So there's no "demand" coming from anywhere as far as I can see, and everything seems to be driven by the boiler thermostat. I still find it all quite bizarre, I must admit.

I am afraid that even though someone fitted a fancy modern controller/time switch to your system, it doesn't mean that it is connected to anything other than the boiler and water pump. (It's like trying to push all the buttons on a modern TV remote control while pointing it at an old black and white TV) All you have behind the controller is 3 wires in and 3 wires out. If your room thermostat is actually still working, all it ever did was switch on and off your water pump or motorised valve.
Jim:(

rooferPete

Hi James,

We have had the technology since the mid seventies that I know of, microbore copper pipes fitted to manifolds all run from an oil boiler, thermostats in the as many as you wanted / needed in the house and the cylinder was fed from one side of the boiler independent of the C/H.

That system except with larger pipes was / is still available even from the humble solid fuel back boilers.

I think part of today's problem came from the oil crisis and the central heating grant system to switch to or install solid fuel back boilers.

The whole domestic industry became price driven, based on the grant that was available so the home owner didn't have to pay too much of their own money which at the time of the solid fuel and the natural gas grants the people hadn't got the money.

Remember the 35% VAT on a bathroom suite ? Yep a jacks was a luxury item according to the VAT man

Motorised valve ??? here missus turn that thing like a tap in the hot press when you don't need the radiators, or better again leave it all alone it's only a shovel of coal or 50p in the meter

Ahhh the memories

.

JamesM

rooferPete wrote:

Hi James,

We have had the technology since the mid seventies that I know of, microbore copper pipes fitted to manifolds all run from an oil boiler, thermostats in the as many as you wanted / needed in the house and the cylinder was fed from one side of the boiler independent of the C/H.

That system except with larger pipes was / is still available even from the humble solid fuel back boilers.

I think part of today's problem came from the oil crisis and the central heating grant system to switch to or install solid fuel back boilers.

The whole domestic industry became price driven, based on the grant that was available so the home owner didn't have to pay too much of their own money which at the time of the solid fuel and the natural gas grants the people hadn't got the money.
.

Hi Pete,
We're showing our age
The technology was there, but it was seldom used. It was sometimes used in "one off" jobs in private houses, but that was the time when they started installing central heating in new estates and the builders didn't allow much in their budgets for it.
Even before the grants, I remember 2 housing estates in South Dublin, 2 of the largest builders in the Country. It was still a big deal to put Central Heating in a new house
One put in a Warm Air system (Hess - horrible tank like thing in the middle of the house - always blowing up :eek: ). The other decided that they would put in a more upmarket sophisticated radiator system, but only allocated a very small allowance for the system. The boiler had to be in the kitchen, the hotpress straight above, and all the radiators on the inside walls, so the run of pipe would be minimal. The timeswitch and the boiler thermostat were the only controls. That was 1972, oil was still cheap and the system actually worked quite well. Some of the original boilers are still running.
See ya,
Jim.