Evohome - boiler on VERY frequently

[erik]

It all depends on your setup, yes

[G4RHL]

It all depends on your setup, yes

Thanks Erik. Have always thought that was what was happening in my set up and noticed it when I removed the hall stat some years ago and installed a heatmiser wireless stat ensuring it was wired in where the original hall one was. Using a meter to see what did what it seemed when the wireless stat said "on" it was power to the pump via I think the three way valve and not power to the boiler. The pump or perhaps the valve then sent power to the boiler. Am sure I researched the point years ago and my heating service company told me the boiler gets its instructions that way and not via the stat direct. Makes sense as you would want the pump on for it all to work so if it does not come in then the boiler is not firing away? My Evohome installer automatically wired the relay up similarly. This is helpful in my case as whilst the boiler may cut out if the maximum water temperature is reached the pump is still on circulating the water to those radiators that want it. I suppose I ought to camp outside my airing cupboard and watch to see if I'm right?

[garmcqui]

That makes sense.

Mine is definitely rigged up so the boiler controls the pump, however the pump is on a lot without the boiler being on (pump overrun etc), I presume there's electronics built into the boiler to operate this.

On another note, I have just disconnected my CH zone valve, opened it manually and configured my BDR91 as a boiler relay. So am hoping this configuration will give me more control over the boiler demands etc. Fingers crossed!

[top brake]

That makes sense.

Mine is definitely rigged up so the boiler controls the pump, however the pump is on a lot without the boiler being on (pump overrun etc), I presume there's electronics built into the boiler to operate this.

On another note, I have just disconnected my CH zone valve, opened it manually and configured my BDR91 as a boiler relay. So am hoping this configuration will give me more control over the boiler demands etc. Fingers crossed!

Good stuff, what is your boiler; gas or oil?

You will also get a 'failsafe' parameter that can be configured to maintain a level of heating if communications are lost
Please don't be tempted to mess with 'internal sensor offset' you will drive yourself nuts and become obsessive about measuring the room temperature with a thermometer

[erik]

Of course, it would help if Evohome was able to show the actually measured temperature instead of some 'rounding' that's always biased (lie'ing) towards setpoint.

[jonstatt]

I've just been thinking - on my (S-plan) system, when the BDR91 sends a boiler demand, the CH zone valve opens and this in turn switches on the boiler. However, as soon as the heat demand from the BDR91 ends, the zone valve closes immediately and boiler turns off. Now there must still be a lot of heat left in the system, but due to the zone valve being closed the heating circuit is isolated so it can't be circulated through the radiators, instead it's just pumped around the bypass circuit for 5 minutes until the pump overrun ends.

This can't be the best way to do it, surely?

That's exactly how a conventional S-plan system always works! Forget EVOHOME and just consider your old set-up. When the thermostat reaches temperature, the zone valve is closed at that moment. The boiler controls the pump as you know, and continues with pump over-run. Over-run is always working through the bypass loop therefore. Maybe you understood that, but I just wanted to make sure it was clear that this was a normal s-plan behaviour and nothing that has been introduced by EVOHOME.

[The EVOHOME Shop]

Of course, it would help if Evohome was able to show the actually measured temperature instead of some 'rounding' that's always biased (lie'ing) towards setpoint.

No offence erik, but your constant negative posts really are boring me. If you have a problem with your product and think it is faulty, sort this out directly with the supplier you bought the product from.

This is a heating controls forum. I did not see a badge saying Honeywell or evohome only posts. This is not a place to start a war with Honeywell.

I have run several forums over the years and people are reluctant to post when there is negativity on each post that someone puts up.

The people who post on the forum want 'constructive' answers to their posts and not to be spammed with your negativity about your own limited experience.

All I can read is top brake and rameses trying to help people who want to know more about the products and you on full attack back at them at every step - this is not nice to read by existing or new forum members.

This is just my 2p and if I was a forum moderator you would be warned for your poor behaviour towards other human beings on this forum who spend their time and experience with you.

[G4RHL]

Of course, it would help if Evohome was able to show the actually measured temperature instead of some 'rounding' that's always biased (lie'ing) towards setpoint.

I used to think this but then the more I have used Evohome the more I wonder whether having a precise reading is so crucial. The reading for the HR92s, in my case, and probably for most, is taken a few inches off the floor. In some cases there may be a draught affecting it if for example someone has gone out of the room. Heat rises so it will be warmer higher up. I do not live at floor level and I find it better to consider what a thermometer at waist level is telling me. To be fair to Evohome in many cases, once a room is up to heat and stable the two are the same or within 0.5 degrees of each other. But 21C one day can feel colder than 21C on another day due to all sorts of ambient conditions, clothing and indeed bodily conditions. Never mind the affects of the odd drop of the hard stuff! I agree that perhaps if I simply used the room stat and not the HR92s to set temperature then I may have more constant accuracy (a point you have often made) but even then putting a Honeywell room stat (I have the new round one) alongside a couple of other stats all three do not always give the same reading and are often 0.5C different between them if not more. Last time I checked this two "independent" thermometers, once they had had time to settle down, always read the same but the Honeywell one was 0.5 or more different. We know the sort of temperature levels that are comfortable for us. For some its more than 21, others want it less (my wife is of the former!) so precise accuracy is not perhaps as important as ensuring the right comfort level without it being excessive.

Incidentally, elsewhere in this forum a member said he has called his custom menu to boost heat "Wife feeling cold". I like that! I may emulate it!

[erik]

@Evohome shop: I have been in contact with the supplier, they were going to take the product back (not working as advertised). But then they got me in contact with Honeywelll to try and solve it instead. I have been in contact with very nice people from Honeywell for a long time now. Awaiting the outcome. No problem there, at all.

My only gripe is that certain people on this forum are constantly ignoring/deny'ing anything that could point to a flaw in the system. They are trying to make it seem like it MUST be the user who's doing something wrong. This is unfair to customers who spent a lot of money on a product and who spent a lot of time reading up on and testing and monitoring the behavior. Why is it so hard to believe something could be wrong?

I've been helpful and constructive in posts, haven't you seen them? It's not just my own limited experience by the way. Many are experiencing the same. I've spoken to several of them on several forums. Lots of them have returned the product. Wouldn't it be better if it actually got solved??? Wouldn't that be better for everyone? Including people who make a living out of selling this product? (you)

In another post I already explained that I don't mind much if there's a mistake in a product, it's only human. What's more important is how it's dealt with once reported. Dismissing everything as user mistake is not the way to go.

@G4RHL: if the reading is not that important, then why do they specifically code it so that it's always shown as if it's closer to setpoint than it actually is? Why not just show true reading (at least in installer mode or something)?

[Otto-Mate]

This thread is now closed.

Members are free to start new threads, however anyone trolling by constantly posting negative remarks will have their membership suspended or terminated.

Thanks for your understanding.

M.