New Boiler - Weather Compensator?
Discussion
EVening all.
The time has now arrived for me to get the boiler replaced, which is being done in a couple of weeks.
Now, at the moment i am running standard S plan, but this is being adapted so that we can zone upstairs and downstairs individually with separate programmable room stats.
However, the latest thing seems to be having the system weather compensated, with the appropriate sensor outside.
From my very basic understanding, is that if the system is WC, there is no need for room stats?
Thats great, but, on occasion there is sometimes the need to give the heating a 'boost', in which case, would be impossible as there is nothing to adjust.
Looking at the installation instructions, it does state that a room stat can be installed as well, but i am struggling to understand how this would work on a WC system?
My gas man who is installing it all is a good friend, but won't really say how it works or even which would be the best way to go.
An idiots guide to this type of set up would be most appreciated!
The time has now arrived for me to get the boiler replaced, which is being done in a couple of weeks.
Now, at the moment i am running standard S plan, but this is being adapted so that we can zone upstairs and downstairs individually with separate programmable room stats.
However, the latest thing seems to be having the system weather compensated, with the appropriate sensor outside.
From my very basic understanding, is that if the system is WC, there is no need for room stats?
Thats great, but, on occasion there is sometimes the need to give the heating a 'boost', in which case, would be impossible as there is nothing to adjust.
Looking at the installation instructions, it does state that a room stat can be installed as well, but i am struggling to understand how this would work on a WC system?
My gas man who is installing it all is a good friend, but won't really say how it works or even which would be the best way to go.
An idiots guide to this type of set up would be most appreciated!
From a laymans point of view, I couldn't see the point of this when we had our boiler installed.
Surely, if the stat is saying it's cold, the boiler has to work harder. Then, if the water coming into the boiler is colder, the boiler has to work harder to get it up to the outgoing temp as specified on the boiler control?
So apart from telling the boiler to work harder, which it already knows due to temp, what does a compensator do?
Surely, if the stat is saying it's cold, the boiler has to work harder. Then, if the water coming into the boiler is colder, the boiler has to work harder to get it up to the outgoing temp as specified on the boiler control?
So apart from telling the boiler to work harder, which it already knows due to temp, what does a compensator do?
Thanks for that.
Yes, thats what i thought but then i read that it seems that the heating is running all the time, with the radiators cooling and warming up depending on outside temp.
If thats the case, i'm not sure why a room stat is needed as the boiler theoretically would control the room temp?
Yes, thats what i thought but then i read that it seems that the heating is running all the time, with the radiators cooling and warming up depending on outside temp.
If thats the case, i'm not sure why a room stat is needed as the boiler theoretically would control the room temp?
vladcjelli said:
From a laymans point of view, I couldn't see the point of this when we had our boiler installed.
Surely, if the stat is saying it's cold, the boiler has to work harder. Then, if the water coming into the boiler is colder, the boiler has to work harder to get it up to the outgoing temp as specified on the boiler control?
So apart from telling the boiler to work harder, which it already knows due to temp, what does a compensator do?
I think the idea is the house is maintained at the required temp, but if the sensor picks up a drop in temp outside, it runs hotter to maintain the desired temp in the house.Surely, if the stat is saying it's cold, the boiler has to work harder. Then, if the water coming into the boiler is colder, the boiler has to work harder to get it up to the outgoing temp as specified on the boiler control?
So apart from telling the boiler to work harder, which it already knows due to temp, what does a compensator do?
What i don't get is why/how a room stat can work in conjunction with WC.
Exactly. A room stat should define how warm the radiators get, with the boiler having to work as hard as is required.
The only benefit I could see is if it takes into account the incoming temperature of water for hot water, increasing effort to maintain constant temp. But surely, the setting of the boiler hot water temp should ensure constant temp out of the hot tap?
The only benefit I could see is if it takes into account the incoming temperature of water for hot water, increasing effort to maintain constant temp. But surely, the setting of the boiler hot water temp should ensure constant temp out of the hot tap?
vladcjelli said:
Exactly. A room stat should define how warm the radiators get, with the boiler having to work as hard as is required.
The only benefit I could see is if it takes into account the incoming temperature of water for hot water, increasing effort to maintain constant temp. But surely, the setting of the boiler hot water temp should ensure constant temp out of the hot tap?
The room stat defines how hot the room gets, the weather compensation alters the flow temp from the boiler. if the flow temp is kept as low as possible the boiler will remain in condensing mode for longer and hence more efficient.The only benefit I could see is if it takes into account the incoming temperature of water for hot water, increasing effort to maintain constant temp. But surely, the setting of the boiler hot water temp should ensure constant temp out of the hot tap?
The heating and domestic hot water have nothing to do with each other and are controlled separately.
silversurfer1 said:
Drayton Lp722 programmer JOB DONE !
SS
All this WC is a load of rubbish nobody except the guys who coded it ever knows how they work !
SS
I notice that unit allows a 1,2,3, hour boost but not a 1,2,3 hour cut back. I've often thought that it would be useful to kill the heating when we're going out for a couple of hours.SS
All this WC is a load of rubbish nobody except the guys who coded it ever knows how they work !
SS
Just reading through the boiler user instructions again (Viessmann Vitodens 100W) and it says that the room temp can be adjusted via the boiler temp control knob if WC is installed.
That was my main concern really.
Also, as we are fitting the boiler to an existing two pipe system, the DHW will take priority over heating, which means i will have to time the hot water to come on and be done, an hour or so before we get up.
But, you can also connect room stats to the WC system, so i am assuming if a room stat calls for more heat, it will over ride WC mode and work normally until the room temp is achieved, and then revert back to WC to maintain the set temp.
My head hurts.
That was my main concern really.
Also, as we are fitting the boiler to an existing two pipe system, the DHW will take priority over heating, which means i will have to time the hot water to come on and be done, an hour or so before we get up.
But, you can also connect room stats to the WC system, so i am assuming if a room stat calls for more heat, it will over ride WC mode and work normally until the room temp is achieved, and then revert back to WC to maintain the set temp.
My head hurts.
Edited by Alucidnation on Sunday 25th May 10:56
Alucidnation said:
Just reading through the boiler user instructions again (Viessmann Vitodens 100W) and it says that the room temp can be adjusted via the boiler temp control knob if WC is installed.
That was my main concern really.
Also, as we are fitting the boiler to an existing two pipe system, the DHW will take priority over heating, which means i will have to time the hot water to come on and be done, an hour or so before we get up.
But, you can also connect room stats to the WC system, so i am assuming if a room stat calls for more heat, it will over ride WC mode and work normally until the room temp is achieved, and then revert back to WC to maintain the set temp.
My head hurts.
You can cap off the two dedicated cylinder feeds and use a standard zone valve setup That was my main concern really.
Also, as we are fitting the boiler to an existing two pipe system, the DHW will take priority over heating, which means i will have to time the hot water to come on and be done, an hour or so before we get up.
But, you can also connect room stats to the WC system, so i am assuming if a room stat calls for more heat, it will over ride WC mode and work normally until the room temp is achieved, and then revert back to WC to maintain the set temp.
My head hurts.
Edited by Alucidnation on Sunday 25th May 10:56
Gingerbread Man said:
Alucidnation said:
Just reading through the boiler user instructions again (Viessmann Vitodens 100W) and it says that the room temp can be adjusted via the boiler temp control knob if WC is installed.
That was my main concern really.
Also, as we are fitting the boiler to an existing two pipe system, the DHW will take priority over heating, which means i will have to time the hot water to come on and be done, an hour or so before we get up.
But, you can also connect room stats to the WC system, so i am assuming if a room stat calls for more heat, it will over ride WC mode and work normally until the room temp is achieved, and then revert back to WC to maintain the set temp.
My head hurts.
You can cap off the two dedicated cylinder feeds and use a standard zone valve setup That was my main concern really.
Also, as we are fitting the boiler to an existing two pipe system, the DHW will take priority over heating, which means i will have to time the hot water to come on and be done, an hour or so before we get up.
But, you can also connect room stats to the WC system, so i am assuming if a room stat calls for more heat, it will over ride WC mode and work normally until the room temp is achieved, and then revert back to WC to maintain the set temp.
My head hurts.
Edited by Alucidnation on Sunday 25th May 10:56
I'm not sure i understand what you mean?
We currently have a standard S plan system in place.
I've also got a Viessmann Vitodens 100W and looked into the WC sensor. As someone above correctly says, the theory is keep the return water at a low enough temp to ensure the boiler stays in condensing mode. Being into automation I started tracking temperatures and gas consumption - which i can track to the nearest decilitre.
What I found is that keeping the water low enough to condense resulted in the boiler running for ages to heat the water tank (which I only heat to around 55'c with a weekly high temp boost to kill the bugs) and the radiators not really heating the rooms.
I found I consumed far less gas by turning the boiler up to level 6 (70'c) as it only needs about 30mins to heat my 250L tank and the house heats quickly.
So i decided not to bother with WC. Btw, I also sussed out which off the shelf thermistor they use for the outdoor sensor - they are only a few quid rather than the price Viessmann charge.
What I found is that keeping the water low enough to condense resulted in the boiler running for ages to heat the water tank (which I only heat to around 55'c with a weekly high temp boost to kill the bugs) and the radiators not really heating the rooms.
I found I consumed far less gas by turning the boiler up to level 6 (70'c) as it only needs about 30mins to heat my 250L tank and the house heats quickly.
So i decided not to bother with WC. Btw, I also sussed out which off the shelf thermistor they use for the outdoor sensor - they are only a few quid rather than the price Viessmann charge.
eliot said:
I've also got a Viessmann Vitodens 100W and looked into the WC sensor. As someone above correctly says, the theory is keep the return water at a low enough temp to ensure the boiler stays in condensing mode. Being into automation I started tracking temperatures and gas consumption - which i can track to the nearest decilitre.
What I found is that keeping the water low enough to condense resulted in the boiler running for ages to heat the water tank (which I only heat to around 55'c with a weekly high temp boost to kill the bugs) and the radiators not really heating the rooms.
I found I consumed far less gas by turning the boiler up to level 6 (70'c) as it only needs about 30mins to heat my 250L tank and the house heats quickly.
So i decided not to bother with WC. Btw, I also sussed out which off the shelf thermistor they use for the outdoor sensor - they are only a few quid rather than the price Viessmann charge.
Ok thanks.What I found is that keeping the water low enough to condense resulted in the boiler running for ages to heat the water tank (which I only heat to around 55'c with a weekly high temp boost to kill the bugs) and the radiators not really heating the rooms.
I found I consumed far less gas by turning the boiler up to level 6 (70'c) as it only needs about 30mins to heat my 250L tank and the house heats quickly.
So i decided not to bother with WC. Btw, I also sussed out which off the shelf thermistor they use for the outdoor sensor - they are only a few quid rather than the price Viessmann charge.
With the WC kit, they supply a hot water demand box, which i believe, over rides the WC/Htg, to heat the water, at a higher temp and then reverts back to heating, a bit like a combi.
I am going to ring them on Tuesday and try and find out exactly how it works.
We have a combi Vaillant WC, which was a good deal when I purchased the boiler.
Everyone else has covered how they work. Obviously it is more energy to heat water to 70 rather than 40, so if 70 isn't needed, then I'd like the boiler not to try. Ours has a curve that allows you to adjust how much the weather adjusts the behaviour of the boiler. Took some fiddling but now it's spot on.
Our gas bills are tiny now so it seems worth it to me.
Everyone else has covered how they work. Obviously it is more energy to heat water to 70 rather than 40, so if 70 isn't needed, then I'd like the boiler not to try. Ours has a curve that allows you to adjust how much the weather adjusts the behaviour of the boiler. Took some fiddling but now it's spot on.
Our gas bills are tiny now so it seems worth it to me.
Edited by untruth on Sunday 25th May 23:56
Sorry about this heating experts but it may simply be down to me being a bit thick.
Our heating settings need to be adjusted dependent upon whether we have prevailing winds or something from the North and East quadrant.
Therefore how will a single WC sensor deal with this or is it just a factor that our internal room stat is on the North side.
Btw I understand that inanimate objects don't suffer wind chill per se before we head off down that cul de sac.
Tired from last night so brain not fully functional this morning.
Our heating settings need to be adjusted dependent upon whether we have prevailing winds or something from the North and East quadrant.
Therefore how will a single WC sensor deal with this or is it just a factor that our internal room stat is on the North side.
Btw I understand that inanimate objects don't suffer wind chill per se before we head off down that cul de sac.
Tired from last night so brain not fully functional this morning.
moles said:
If you haven't already purchased the Viessmann i would have a rethink, they are not one of the most reliable boilers out there!.
Interesting that you say that, as I haven't seen many complaints on the internet about them, and we all know how quick people are to post up problems, plus they offer a 5 yr warranty, and a 10yr warranty on the heat exchanger.WB and Vaillant seem to be the ones most people choose, but I have heard from several gas installers that they can be problematic when they are fitted to older systems, and can be quite picky when it comes to warranty claims.
What would you recommend?
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