Central Heating Question.

[securespark]

I am ashamed to say I don't know what type of CH system we have, save to say I know there is a 3 way valve under the floor upstairs.

There are TRV's everywhere bar the bathroom. There is no room stat.

The programmer is a Honeywell:

I'm not sure if this is enough to go on, but here goes anyhow:

Mrs Secure would like to fit some kind of 1 hour (or maybe a settable) "boost" ie, to be able to override the off period and switch on the heating only for a preset period.

Is this just a case of fitting some kind of timeswitch/ boost switch across the live & the feed to the pump or is it more complex?

I haven't had the time to trace all the wiring from the programmer outwards to let you know exactly how it's wired. Is this enough to go on or not?

Cheers, guys!

 

[Spark123]

Sounds like either a Y or a W plan.
I wouldn't connect it to supply the pump as this may be operated along with the boiler from the micro switches inside the valve - I'd look towards putting it across the contact which calls for C/H on the timer.

 

[Taylortwocities]

Secure, the easiest way is to swop your old programmer for something like this. http://www.tlc-direct.co.uk/Products/HOH21.html

This Horstmann ChannelPlus programmer has separate 1 hour boost buttons for water and for heating. Its all modern and has an LCD display!

There are others in the range that do 2 hour boost too.

They come with an idiots guide to replacing the old one (I use this a lot!)...

 

[gas4you]

Yes you have a 'Y' plan.

I agree the easiest way is to replace the programmer with a modern one.

If you go for a full programmer eg Danfoss FP715si or equivalent, you will also gain total seperate control over the heating and hot water as well as 3 on/offs per day each channel and different times for each day as well.

The Danfoss is about £50 + VAT, or if you want a spare 3 way valve, room stat and cyl stat, get the Danfoss FP715si heatshare pack for about £55 + VAT

 

[JohnD]

with that programmer, Mrs. S could press the "change +" button and it will turn on the heating (if it is already off) without changing the programmer settings. The programmer will return to programmed settings at the next programmed event.

If she presses the "change -" button it will turn the HW on.

She will have to press it again in an hour's time if she wants to turn them off, though, if she is hung up on the "one hour boost" idea. If you had a wall stat, it would turn off the CH once the house was warm.

If she presses it when they are already on, it will turn them off. It it just a one-time "override" change state button (although it is also used, in conjunction with the top lever, to change programmer settings).

BTW I have one of those, I specified it because it is nice and simple and I have found 7-day digital programmers too wearisome to fiddle with.

And you ought to have a wall stat, or you are tipping money down the drain. You can pick up the wiring diagram off the Honeywell website. Your programmer is an ST699. Or if you send me £100 I will photocopy my instructions and send you a copy

 

[Chri5]

Or free via this PDF

http://www.screwfix.com/sfd/i/cat/pdfs/41/p4734641.pdf

And if you spend £30 of the £100 saved, you could take a day out at Honeywell for the domestic heating controls installation design, slection and wiring course.

http://www.honeywelluk.com/article.aspx?ai=training

 

[securespark]

Thanks a lot, guys!

So, a change of programmer might be the easiest way to solve the problem.

If I go for a room stat as you advise, would a programmable one be good?

Ease of installation would be good (thanks TTC!), but how about ease of programming & use? Anybody have any recommendations?

Otherwise, I might just go for your choice, TTC, along with a matching stat.

with that programmer, Mrs. S could press the "change +" button and it will turn on the heating (if it is already off) without changing the programmer settings. The programmer will return to programmed settings at the next programmed event.

If she presses the "change -" button it will turn the HW on.

Thanks, John. We did work this out, after a couple of years.....! But we are forgetful folk & a boost you can press & forget would be very handy.

Edit: Just had a look at the Horstmann link, TTC... It suggests Honeywell is compatible with their products, but not the one you link to.

You can tell I'm not much of a CH guy.....

 

[hairyben]

If 7 day or 5/2 is required I fit the drayton tempus 7, mostly cos it's quite user friendly.

Its has boost buttons for both CH and HW, 1press for 1hr, 2 press for 2hr

If 24hr is all thats needed then a siemens RWB2E is a good choice

TRV's everywhere means no need for a programmable roomstat, unless you want a night set-back mode

 

[securespark]

HB: John suggests a room stat to save money. I currently have no room stat at all. Is there no need with a housefull of TRV's or is it a wise addition.

My BG service engineer says their systems have room stats whether fitted with TRV's or not.

I'm confused.com!!

 

[gas4you]

Current regulations for new installs and boiler changes state you must have TRV's on all rads except the room in which the room stat is fitted, usually the hall or the lounge.

Go for a Honeywell wireless analogue room stat, just a basic stat and change your main programmer. Job done.

 

[Diyisfun]

The advantage of having a room stat as well as trvs, is that you can turn all the heating off at one stroke, & yet it will resume to normal at the next sequence that is set (thats assuming you have the right t/sta fitted, I do).

 

[ban-all-sheds]

Did you use a Kango to make the mounting holes in the wall?

 

[hairyben]

The advantage of having a room stat as well as trvs, is that you can turn all the heating off at one stroke, & yet it will resume to normal at the next sequence that is set (thats assuming you have the right t/sta fitted, I do).

And a programmer can't do that?

In the old days you had a roomstat, which sort of worked if your system was well balenced and you wanted the same temp everywhere, or you had TRV's and could set different temps wherever you liked. Then the stupid government came up with a regulation that says everyone must have a roomstat regardless of the total pointlessness of it where TRV's are concerned, because apparently you're more likely to turn the heating down and be eco-sensitive if you have a stat on the wall.

That said, programmable stats are a good idea if you want automatically varied temps or a night set-back, ie 20 during the day, 25 in the evening and 15 at night.

 

[JohnD]

Perhaps he used his electrician's joist-notching and wall-chasing tool?

BTW a roomstat tells your boiler not to run when the house is warm. Otherwise, even when all the TRVs are shut, it will continually try to bring itself, and any pipes it can reach, up to 70C or thereabouts, which is wasteful and unnecessary. You may have a bypass under the floor or somewhere that the pump squirts through when all rads are off.

CH is not like an electric fire that you have to turn on and off depending on how cold you feel.

 

[Steve]

BTW a roomstat tells your boiler not to run when the house is warm. Otherwise, even when all the TRVs are shut, it will continually try to bring itself, and any pipes it can reach, up to 70C or thereabouts, which is wasteful and unnecessary. You may have a bypass under the floor or somewhere that the pump squirts through when all rads are off.

Ah but the boiler isn't heating all the rads, its only heating one, the bypass. Ours is in the bathroom, above the boiler, a towel rail. Thus theres only a short length of pipework to it. The bathroom normally has the window ajar, so it requires the heat all the time.

The woman of the household is forever turning the TRVs right up to dry washing, or because she's cold, which gets right on my tits. Especially the one in the kitchen. I'm always going in there and its red hot, because shes cooking. Rads still on. I point out the error of her ways, but it gets us nowhere sadly.

I think she assumes because the boiler is running and making a noise, its using full power, therefore we must utilise all that heat!

My dad recently turned MY TRV right up, I turned it back to 3, and stuck a note on it saying "dont even think about it"