Has anyone had any success in preventing their boiler from short cycling?

This is quite confusing tbh.

Short cycling won't cause the house to be cold and be unable to get up to your desired temp (E.g. 20degsC). As it's a newish house, it will be insulated well, so even with fairly small rads and a high flow temp (70degsC) it will heat up quickly and easily with the above setup. Unless the house is massive, an average 150m2 4 bed detached probably has a heat loss of 5.5-6kW MAX on a -3degC day. Your rads would have to be A4 sized single panels to not be able to heat the place up.

Are all the rads warming up and feeling very hot to the touch (use back of hand)? You ideally need to find out what the temperature of the water is entering and leaving the rad, get a cheap IR thermometer (wrap the pipe in black tape to help get a point reading).

I wouldn't worry about boiler range rating settings or flow temps until you can confirm to us the rads are working and the house gets up to 20degC internal temp and stays there. Start with one thing at a time to troubleshoot, rather than trying everything under the sun where you'll just get confused and not end up figuring out what the main problem is.
 
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Morning everyone,

Thanks for your replies. I got annoyed by the whole thing so tried to stop thinking about it over the weekend.

As @squerble says, the boiler can't module down enough. It was set to 18 kW heating output!!! The house is three bedrooms, around 65 m2, so I think the peak heat demand is somewhere around 3 kW, assuming a terrible heat loss of 40 kW/m2. The boiler can only go down to 7 kW, so basically it's dramatically oversized. Therefore, the cycling problem won't ever go away, annoyingly.

I seem have got it to a relatively decent place over the weekend. The outstanding issue is that one thermostat is behind the TV, so when the TVs off it works fine. When the TV's on it gets a dodgy reading, so the thermostat has to be adjusted for that. I think I need to convert it, somehow, to a wireless one. Unfortunately, it's all Honeywell and I have no intention of changing all of it to something smarter.
 
dirtychinchilla said:
Morning everyone,

Thanks for your replies. I got annoyed by the whole thing so tried to stop thinking about it over the weekend.

As @squerble says, the boiler can't module down enough. It was set to 18 kW heating output!!! The house is three bedrooms, around 65 m2, so I think the peak heat demand is somewhere around 3 kW, assuming a terrible heat loss of 40 kW/m2. The boiler can only go down to 7 kW, so basically it's dramatically oversized. Therefore, the cycling problem won't ever go away, annoyingly.

I seem have got it to a relatively decent place over the weekend. The outstanding issue is that one thermostat is behind the TV, so when the TVs off it works fine. When the TV's on it gets a dodgy reading, so the thermostat has to be adjusted for that. I think I need to convert it, somehow, to a wireless one. Unfortunately, it's all Honeywell and I have no intention of changing all of it to something smarter.
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If it's just a dumb controller the swap to something better is pretty cheap and quite easy.

Amazon even offer the Hive unit (not quite as good as the Tado X but British Gas backed) with installation for +120 quid.
 
dlockers said:
If it's just a dumb controller the swap to something better is pretty cheap and quite easy.

Amazon even offer the Hive unit (not quite as good as the Tado X but British Gas backed) with installation for +120 quid.
Click to expand...

Is that cheap, though?!

It's much more likely to be something like this:

 
dirtychinchilla said:
Is that cheap, though?!

It's much more likely to be something like this:

Click to expand...
If you're not looking to go for something "smart" (i.e., internet connected) then this would be fine.

EDIT: The tado and Hive linked by @dlockers are nice but be aware they runs on something called TPI when used as an "on/off" mode thermostat, meaning they'll kick the heating in and out for 5 minutes here and there to maintain temperature. This will further add to the cycling and honestly would be best avoided. I got a pair to replace basic on/off programmables and hated the TPI mode so went back to the basic ones we had.
 
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squerble said:
If you're not looking to go for something "smart" (i.e., internet connected) then this would be fine.

EDIT: The tado and Hive linked by @dlockers are nice but be aware they runs on something called TPI when used as an "on/off" mode thermostat, meaning they'll kick the heating in and out for 5 minutes here and there to maintain temperature. This will further add to the cycling and honestly would be best avoided. I got a pair to replace basic on/off programmables and hated the TPI mode so went back to the basic ones we had.
Click to expand...

No, it doesn't need to be smart. I'd like it to be, but I don't see the value in it right now.

I'll just get that one from Screwfix and be done with it. Thanks :)
 
squerble said:
If you're not looking to go for something "smart" (i.e., internet connected) then this would be fine.

EDIT: The tado and Hive linked by @dlockers are nice but be aware they runs on something called TPI when used as an "on/off" mode thermostat, meaning they'll kick the heating in and out for 5 minutes here and there to maintain temperature. This will further add to the cycling and honestly would be best avoided. I got a pair to replace basic on/off programmables and hated the TPI mode so went back to the basic ones we had.
Click to expand...
The Tado X supports OpenTherm which if he has the right wiring center will be a significant upgrade over the HoneyWell
 
dlockers said:
Sorry I missed it is a Vaillant. Can you post a pic of your wiring center? If you have the proper vaillant one, you are best off with a Vaillant controller as it supports a proprietary version of OpenTherm.
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The wiring centre is probably just the usual chock block with everything unlabelled :p
 
dlockers said:
Sorry I missed it is a Vaillant. Can you post a pic of your wiring center? If you have the proper vaillant one, you are best off with a Vaillant controller as it supports a proprietary version of OpenTherm.
Click to expand...

squerble said:
The wiring centre is probably just the usual chock block with everything unlabelled :p
Click to expand...

I think it is. Either way, I'm not going to install OpenTherm
 
dirtychinchilla said:
I can stretch to £75 :) I don't think UK heating systems are good full stop. I don't necessarily think the smart ones are much better
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Good boilers (read, those that can modulate very low like the Viessmanns) combined with weather and/or load compensation can be very good and comfortable :) even with our oversized boiler and simple on/off stats, I've been able to do a bit of "manual OpenTherm" by changing flow temperature as temperatures fluctuate. The heating runs a lot longer with less variation in temp - doesn't stop it short-cycling, mind.
 
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