Heating System Controls

[securespark]

Just wanting a bit of advice about our heating system controls.

It is an electric system, switched via contactors.

There is one system for upstairs and one for down.

The system upstairs is controlled by a tamperproof stat Sunvic TLM 2543 and an Electrisaver E30 to provide a limited, timed "ON" period.

The system downstairs is controlled by a Sunvic digital stat and an electromechanical time switch to provide a limited, timed "ON" period.

This one:

There is also what I assume to be a frost stat (Sunvic TLX 2360)

on the whole system.

I guess you could replace the adjustable stat downstairs with one like upstairs, ditto the boost switch?

 

[RF Lighting]

Is this for the scout hut again?

 

[securespark]

Yup.

I'm not going to mess about with it until I understand fully how it's been set-up.

There's a Siemens RWB27 programmer for each floor. These have been set to come on and off at various times to coincide with hall hire etc...

But now we just want to scrub those pre-programmed times (the programmers are locked away), leaving the system off, and just switch the system via the "boost" switches, which are accessible.

As I mentioned, there is a frost stat on the ground floor, near the timeswitch pictured, which I guess switches the whole system on below 5 degrees.

There is crazy talk of getting rid of the frost stat (ie system off until heat called for by the boost buttons) and hanging the consequences if there's a burst, but I think that's nuts and if I've got anything to do with it, I'm not disconnecting it.

 

[securespark]

Oh, and that clock, it doesn't have a neutral connection, so I guess it is driven purely mechanically?

It's Superswitch, isn't it?

Think I'm showing my age again...

 

[Chri5]

What are you trying to do?

Are your trying to keep as is, or would it be better starting from today's tech and working back?

Boilers are boilers, but there is a wide berth between modern day, and what worked well a few decades ago regarding ch controls. Zone control, multi event, multi zone event, multi stat, blah..

I hate ch work because I do, but I dislike adding new to old even more

 

[RF Lighting]

It sounds to me as though your b uilding is set up pretty similar to ours, although ours is just a single floor with one heating zone.

We have tried all sorts of different controls over the years and eventually settled on the following:

We went with a danfoss randall 852 programmer as it requires a key to alter anything at all on it, which we had all sorts of issues with people pressing buttons trying to get the heating on, despite it being in a locked electric cupboard with notices on telling them not to touch it.

We use one channel for the heating, and the other for hot water. It's all electric and feeds a 60A and a 20A contactor respectively.

For the heating, the clock supplies a honeywell roomstat set at ~19°C. This stat is fitted with the front off a frost stat so it can not be altered.

There is a room stat in the hall which is also fed from the time switch, and can be adjusted from 15°C to 25°C. This stat switches on a neon indicator, but does not control the heating. It is installed just to pacify the leaders' obsession with messing with the heating. We call this the 'comfort stat'

Next to the comfort stat is an electrisaver push button.

This is wired in parallell with the supply and output to the time switch, so supplies both stats. It's basically an idiot proof boost for the timer for if there's a booking which isn't one of the usual weekly bookings.

Then we have the frost stat which is set to about 5°C. This is fed from the clock feed, and switches the contactor on regardless of what anything else is doing.

We used to have those convector heaters as per your OP, but they were useless. We went with 3 low surface temperature electric radiators, and they've been fantastic.

Hope that makes sense to you!

 

[securespark]

Yeah, we too have an all-electric set-up. It would appear that we have also had many a set-up over the years since the place has been open (51 years). In our case, the programmers are locked away and only the leaders have access to the keys. The stats are only fiddled with by MOP's, the leaders leave them alone, as they do the programmers.

I have been told our upstairs set-up (except the heaters and the programmer settings - see other thread) is perfect. They want to replicate this downstairs. As per the other post, the upstairs set-up is fed via a programmer, with a tamper-proof stat set to 16 degrees. Adjacent to this is an electrisave E30, just like yours.

We don't have a dummy stat! Great idea, though!!

Like you we have the programmer set up for regular on & off periods, and use the E30 upstairs for a short timed boost.

We too have a frost stat set to 5 degrees.

The changes we want to make are minimal.

Basically, we want to do away with the timed on/off periods on both programmers, so that the system is effectively off (save for the frost stat kicking in) until the boost switch is operated

We want to replace the accessible adjustable stat downstairs with a tamperproof one like the one upstairs.

Then we want to replace the timer switch in the picture with an E30 like upstairs, or maybe an E15, as they have a maximum of 1 hour's boost time.

Then, if deemed necessary, we may need to change the wall-mounted heaters upstairs. With that in mind, what brand are the low surface temperature electric radiators you make mention of??

I know you may frown on making it a manual-only system, but does it seem feasible?

 

[securespark]

The TLM 2453 is able to be wired both with and without a neutral.

http://www.tlc-direct.co.uk/Technical/DataSheets/Sunvic/TLM2453.pdf

The downstairs stat has no neutral, but I could get one to it without too much difficulty.

The stat presumably will be more accurate with a neutral connection, so is it worth doing?

 

[RF Lighting]

Simon, I don't see any issues with going to a fully manual system. The only reason for us using a timer is so the heating comes on about 30 mins before the groups come in, so the building is already on its way to being warm for them. You might get a few moans from people coming in to a cold building, but if your not bothered about that, then it'll be fine.


If it's not too much hassle then it will be worthwhile getting a neutral to the stat position, as they do work better with a neutral.


The radiators we used were from this place:

http://www.easy-heat.co.uk/default.aspx

They're based in halifax, so not too far from either of us. I can't remember what we paid as it was a few years ago, but I've got a feeling it was something like £400 - £500 for a 600mm x 1500mm rad including the LST cover. We heat our building with three of these, plus a tubular heater in the toilets.


You're more than welcome to come accross and have a look at our setup if you like, just give me a shout.

 

[securespark]

Rob, a thousand thank you's for your advice and kind offer. This is an on-going issue so I may well have a look at your set-up, but I've still not returned to driving yet...

 

[RF Lighting]

If you want to come on the train, let me know. I'll pick you up from the station.

 

[securespark]

Wow!

I may just do that, but I'll have to look at the calendar first!

Thank you.