Help on central heating boiler please

[brian08]

This is driving me up the wall so I hope someone here can help.

Had a new boiler, Veismann 100, put in during summer but it has underperformed since the central heating went on. It seems to take ages (eg 12 hrs) to reach required temp (21c) on mild winter days (8 or 9c outside) and gets nowhere near it on real cold days (2c or less). CH plumbers have been back several times and tend to blame existing pipework.

I have pointed out that boiler manual says bolier water temperature range is 30-80 yet if I put it on highest no (6) temp reads only as 65c and if I push as far as I can (before hitting a reset point) it increases to 68c. This doesn't seem right but cuts no ice with CH plumbers (local firm)

Any comments/suggestions please.

 

[Axel]

Turn off valves on all but 1 radiator. If the boiler water temp won't go to max of range, call the installer / boiler manufacturer.

 

[spraggo]

This is driving me up the wall so I hope someone here can help. Any comments/suggestions please.

An undersized pipe gas supply to the boiler would be a good reason for this.

 

[brian08]

Thanks for those replies. Can I assume from those that you think the reason the rooms can't reach temperature is that 68c is not high enough (for whatever the reason).

 

[D_Hailsham]

What controls (programmer and thermostat) do you have?

 

[brian08]

For D.Hailsham

There is a Honeywell programmer/thermostat for the CH in the hallway. The radiators also have temperature controls. They appear to work correctly as you can manipulate the boiler by adjusting the thermostat.
The Hot Water cylinder has it's own thermostat.

 

[D_Hailsham]

There is a Honeywell programmer/thermostat for the CH in the hallway.

So you don't have weather compensation - which eliminates that as a reason.

Which Honeywell do you have?

The radiators also have temperature controls. They appear to work correctly as you can manipulate the boiler by adjusting the thermostat.

Do you mean you can manipulate the boiler by adjusting the rad temp controls or are you talking about the Honeywell in the hall?

 

[brian08]

Sorry the Honeywell are the radiator controls. The controlling Thermostat ia Sunvic (I had assumed it was a Honeywell until I looked for a model no). It is this Sunvic thermostat I adjust to temporarily knock off the boiler by reducing thermostat setting. Note however high I set the thermostat, the bolier water temperature doesn't move (I suppose that's obvious but just in case).

I hope that is clear.

 

[D_Hailsham]

Sorry the Honeywell are the radiator controls.

OK

The controlling Thermostat is a Sunvic. ... It is this Sunvic thermostat I adjust to temporarily knock off the boiler by reducing thermostat setting.

Note however high I set the thermostat, the bolier water temperature doesn't move (I suppose that's obvious but just in case).

That's to be expected. The Sunvic only controls the room temperature by turning the boiler on and off. The boiler temperature is controlled by the boiler thermostat.

I assume you have the 100-W boiler. Is it the combi version?

Was an outside temperature sensor fitted?

 

[brian08]

It's not a combi. There is no outside temperature sensor fitted. Yes it is 100-w.

Do you think the max 68c necessarily indicates a problem?

 

[Gasman77]

How long does it take for your rads to get hot?

 

[simond]

You turn the boiler temp knob ALL the way round until it hits the end stop.

The reset function requires you to turn it fully clockwise and then back it off.

Should get to around 75c.

 

[brian08]

Gasman77 - The radiators get hot to touch quite quickly.

Simon - I guess you might be right though odd that plumbers (we've had 3) don't seem to think that's the issue. Quite mild here at mo but will give it a go on next cold spell if nothing else materialises.

Thanks for all the contributions.

 

[Axel]

Pardon me - wrong topic reply!

 

[simond]

What do you mean, give it a go if nothing else materialises?

Are you a buffoon, you posted a problem, you wasted three plumbers time and a load of people on here, I give you the answer and you can't be bothered to turn the boiler knob up?

I only fit Viessmann boilers, why should I know? You'd be so much better getting in another bathroom fitter.

I guess it boils down to you wanting it to be a boiler fault, rather than a customer 'finger problem'.