Vaillant ecoTEC plus open vent (Questions)

Amnesia180

Hi All,

I've recently had a 'Vaillant ecoTEC plus open vent' installed.

However, it seems I'm going to need to have the timer on MORE than my previous gas boiler.

I've found that it seems to drop temperature pretty quickly. I.e: within a few hours it has gone from 65 degrees (the temperature the water boils to) down to 21 degrees in approximately 3 and a half hours.

Can anyone shed any light on this?

Many thanks,
Amnesia

ollski

That's the temperature of the water circulating, or standing, at a certain point in the boiler. When there is no demand it won't take too long to drop down to room temperature.

Amnesia180

Okay thank you.

So how do I get the temperature of the water to stay hotter for longer? Just run the boiler for more hours during the day?

Surely that is defeating the object of money saving if I've got to run it for more hours than my previous one?

alleycat`

If your system is Open Vent it heats a seperate hot water tank?
The temperature on the boiler is showing the temperature of the water flowing through the boiler not the temperature of the water in your tank.

The temperature of the tank is controlled by a thermostat attached to it (usually set around 60C) which will tell the boiler to shut off when it is up to temperature.

I suspect you need the installer to give you a quick guide/explanation over your heating system and what the readings on the boiler refer to as i don't think they mean what you think they do.

ollski

is it the combi version or do you still have your hot water cylinder?, if you have a cylinder then the temperature of the water in the boiler can be 21 wheras the water in the cylinder can be at 60. If it's a combi then the temperature will only rise when you run the tap. In short the display on the boiler means very little!

gas4you

Assuming it is a 400 series, as they are the only open vent Vaillant do, which one is it? 415, 418 etc etc.

When the display temp is dropping and you think it should be on, press the 'i' button and see/tell us what 'S' code is showing.

At the moment my guess would be S53.

You could try setting 'd2' to 5 as an experiment

daveyjp

alleycat` wrote: »

I suspect you need the installer to give you a quick guide/explanation over your heating system and what the readings on the boiler refer to as i don't think they mean what you think they do.

Or read the manual. They can sometimes be useful!

Amnesia180

Thanks all for the very helpful replies.

I have not got a manual as the installation guys took it away to give to the landlord (at landlords request).

It is the 418 version, and yes it is an open vent one heating a separate tank. For some reason the dial on the front of the water tank was around 50.... maybe that is why I feel the temperature has not been as hot as it used to be. Would there be a reason for the installation engineers to have reduced this?

I thought I would have to run the boiler for longer to ensure the temperature on the display stayed up at around 65... However, as you've pointed out to me, this displays the temperature of the water flowing through it (not the water in the boiler).

This one clicks off when it is hot enough... does this mean that even though I have set my water to boil for an extra half an hour in the morning and an extra half an hour in the evenings... it will not necessarily cost more because if it is at temperature it will automatically shut off?

This boiler also does the heating... any tips for money saving on the heating as before this system was installed it was not hooked up to the control panel that controls the hot water... it was just an on/off switch on the heater.

alleycat`

daveyjp wrote: »

Or read the manual. They can sometimes be useful!

Assumed they didn't have the manual and the OP has confirmed that to be the case

alleycat`

Amnesia180 wrote: »

It is the 418 version, and yes it is an open vent one heating a separate tank. For some reason the dial on the front of the water tank was around 50.... maybe that is why I feel the temperature has not been as hot as it used to be. Would there be a reason for the installation engineers to have reduced this?

I thought I would have to run the boiler for longer to ensure the temperature on the display stayed up at around 65... However, as you've pointed out to me, this displays the temperature of the water flowing through it (not the water in the boiler).

This one clicks off when it is hot enough... does this mean that even though I have set my water to boil for an extra half an hour in the morning and an extra half an hour in the evenings... it will not necessarily cost more because if it is at temperature it will automatically shut off?

If you have a hot water tank it should be on or around 60C (doesn't have to be all the time but quite regularly).
This is to stop Legionella forming in the water.

The stat on the hot water tank should tell the boiler to turn off when it reaches temperature so the amount of time you set it to come on is only relevant if the tank doesn't attain temperature or you run a lot of water off for things like a bath.

If properly insulated and the tank isn't huge it should take less than an hour to get it up to 60C and probably one extra heat up of about 40 minutes to make sure it stays there each day.

daveyjp

alleycat` wrote: »

Assumed they didn't have the manual and the OP has confirmed that to be the case

The OP has the internet, they therefore have the manual.