Ideal Logic Weather Compensation Wiring

[MNW67]

We want to stick with heat only (open vent) for our new boiler and my other half wants a boiler which every RGI will know well. Ideal Logic seems to be one of the few heat only boilers which allows PDHW natively. But I am having a problem understanding the wiring diagram:

The wiring diagram relies on using the the HW OFF terminal on the timer. But AFAIK, S-Plan does not use HW OFF. Our existing programmer certainly isn't wired that way.

As far as I can see from the diagram, when there is no timer call for DHW, the HW OFF wire sends a signal to SL2. Presumably, this signal tells the boiler that CH only is required. And the boiler will then set the flow temperature according to the weather compensation curve. If that is the case, why can't the CH motorised valve be wired directly to SL2, instead of this weird rigmarole of using the HW OFF.

 

[MNW67]

I think I've worked it out now. The boiler's internal logic also has to be able to work with Y-Plan. So that is why it has to be done the way shown in the manual.

 

[Daveydub]

With heating only the boiler temperature is controlled by o/s sensor.
If hw is then required, boiler would not give enough heat to get the cylinder hot.
Hw on will override o/s sensor till cylinder is satisfied then hw off will hand back control to o/s sensor

 

[Exedon]

We prefer to fit the ideal vouge when going for pdhw
We go for X plan using a normal open zone valve to shut heating flow when there is a dhw demand.
With a correctly sized cylinder with high performance coil very quick dhw re heat is possible.
When wired correctly with a o/s sensor the boiler display will show what room temperature you want when heating temperature is used,heating flow temperature displayed when heating running.

 

[MNW67]

I know a little bit about the Vogue set up from previous posts and sort of understood the wiring for PDHW and the X Plan. I thought the wiring for the Logic would be the same and that the Vogue's X Plan set up could also be used on the Logic. But it looks totally different. SL1 and SL2 seem to do different things on Logic and Vogue. I think Vogue only comes as a system boiler, not OV.

 

[Daveydub]

You can actually ignore the hw off connections, they just connect to each other and nothing else.
It is a diagram adapted from a y plan diagram.

 

[MNW67]

I thought that might be the case.

I vaguely remember a fully worked up wiring diagram for PDHW on a Logic. I have a feeling it was provided by Sim the Urban Plumber on his website. But I can't find it now. I wish I had saved it!

 

[Deleted member 325366]

Take the advice above and get an Intergas.

 

[MNW67]

Take the advice above and get an Intergas.

Intergas and Alpha were actually my preferred options. But my other half wants something more mainstream, which she believes can be quickly fixed by pretty much any RGI if it goes wrong.

Alpha have a neat half way house solution where you can buy a relay board which overrides the weather sensor when there is DHW demand. It's not full PDHW, but it sounds good enough for us. It also has several other interesting features.

I have read there is a man called Dan who knows everything Intergas. Which might be handy because their own technical support didn't really seem up to speed with PDHW when I rang them last year.

 

[Deleted member 325366]

Intergas and Alpha were actually my preferred options. But my other half wants something more mainstream, which she believes can be quickly fixed by pretty much any RGI if it goes wrong.

Alpha have a neat half way house solution where you can buy a relay board which overrides the weather sensor when there is DHW demand. It's not full PDHW, but it sounds good enough for us. It also has several other interesting features.

I know there is a man called Dan who knows everything Intergas. Which might be handy because their own technical support didn't really seem up to speed with PDHW when I rang them last year.

It’s just a resistor to bypass the WC. I wouldn’t say Alpha are main stream, just doubt you’ll find anyone who knows much about them.

Ideal logics are the simplest boilers on the market. They don’t have any settings other than temperature.

Dan know his stuff!! I’m not a fan of stored water unless it’s needed, as in, more than one bathroom in full time use.

Boiler slingers will tell you ideals are great. Boiler repair men won’t!

 

[MNW67]

It’s just a resistor to bypass the WC. I wouldn’t say Alpha are main stream, just doubt you’ll find anyone who knows much about them.

Ideal logics are the simplest boilers on the market. They don’t have any settings other than temperature.

Dan know his stuff!! I’m not a fan of stored water unless it’s needed, as in, more than one bathroom in full time use.

Boiler slingers will tell you ideals are great. Boiler repair men won’t!

My other half wants Ideal or WB. I'd like something a bit more configurable.

I did some tests and calculations last year, and even though it's a big house, we only need 15kW.

The Alpha has a very similar stainless steel heat exchanger to the Worcester 1000. Single pass with a wide coil. So shouldn't get clogged, even on OV. It looks like Alpha are becoming a bit more popular. I've read that they are actually very reliable. But that they don't have a great repairs service.

 

[Deleted member 325366]

My other half wants Ideal or WB. I'd like something a bit more configurable.

I did some tests and calculations last year, and even though it's a big house, we only need 15kW.

The Alpha has a very similar stainless steel heat exchanger to the Worcester 1000. Single pass with a wide coil. So shouldn't get clogged, even on OV. It looks like Alpha are becoming a bit more popular. I've read that they are actually very reliable. But that they don't have a great repairs service.

Some Worcester’s have great settings and can be range rated. I know Alpha are reliable but as you said, the after sales service doesn’t match!

Ideal are the bog standard boilers for landlords and boiler slingers. They are reliable until L2 appears and that can cost a fortune.

Intergas can do it all. You just need someone who can set one up properly.

With your system cleaned and a decent filter fitted, the heat exchanger shouldnt matter really.

I’ve got mine set to 18kw and it modulates down well below 10kw. But for hot water it’s over 30kw “combi”

As I’ve said, why have stored water, unless you need it ? The Intergas can be set to combi and back to OV later

 

[MNW67]

Some Worcester’s have great settings and can be range rated. I know Alpha are reliable but as you said, the after sales service doesn’t match!

Ideal are the bog standard boilers for landlords and boiler slingers. They are reliable until L2 appears and that can cost a fortune.

Intergas can do it all. You just need someone who can set one up properly.

With your system cleaned and a decent filter fitted, the heat exchanger shouldnt matter really.

I’ve got mine set to 18kw and it modulates down well below 10kw. But for hot water it’s over 30kw “combi”

As I’ve said, why have stored water, unless you need it ? The Intergas can be set to combi and back to OV later

Probably fear of change. We are very happy with the way our hot water works. Also, if we went to a combi, we might need three new high pressure showers fitting.

The problem I had last year with Intergas was getting info on how to do PDHW with two zone S Plan+. I know there is the EPH solution, but I would prefer to use a built in solution.

I think to get a WB Regular boiler with good settings you need to get the 8000. Which has minimum 30kW. I have thought about it, though. It still won't do any sort of weather compensation or PDHW on the regular version.

I was thinking about why other manufacturers like Vaillant have ditched SS on OV. But they used to use the Sermeta/Giannoni HX which has very narrow channels. The Alpha has wide channels like the Vokera SS one. My worry is after sales and repairs with Alpha. But I have read the same about Intergas.

 

[Deleted member 325366]

The problem I had last year with Intergas was getting info on how to do PDHW with two zone S Plan+. I know there is the EPH solution, but I would prefer to use a built in solution.

It can be done with any controls. I’ve got a X plan wiring plan if it helps ?

 

[MNW67]

It can be done with any controls. I’ve got a s plan wiring plan of it helps ?

A wiring plan would probably help! Thanks. Although, I had a look at some last year and got very confused. I understand how the S-Plan and also the single zone X-Plan on Intergas work. The problem seemed to be getting a plan for two zones using PDHW and standard (non EPH) controls. Also, there might have been a difference in the wiring between the Xclusive and the ones which did OV. I tried really hard last year to work it out, but I have forgotten most of it.