CHS not heating house - HELP

[lddex]

Hello,

I am looking for advice and ideas. I moved into my house 2 years ago with a Valiant Eco Pro 28 combiner's boiler. The Radiators look pretty old and have recently just found out that the previous owner had installed the system himself.

I had the boiler looked over and a NEST installed as there was no thermostat. The boiler seems to be working and passed its tests, and heats the water fine.

However the house never reaches temperature. It can take 3 to 4 hours to raise the house 2 or 3 degrees, and the boiler seems to be running flat out, judging by the gas flame on my smart meter.

I at first thought it might be insulation or draughts. But my log burner, seems to heat house in 15 to 20 mins.

I have even changed the radiators upstairs. When the CHS is on, the radiators are all hot to the touch, and are burning. The flow is set at 68 degrees and according to the boiler the return flow is coming back around 62/64 - so not loosing that much heat but the radiators are very hot to touch.

So, what is going wrong. Is it a combination of bad boiler, not being installed correctly, wrong pipework, what radiators. (the new ones have been sized for the rooms) or is it just a very draughty house, that the CHS can't heat quick enough for the speed in which heat is lost.

Look forward to your ideas and suggestions.

Thanks

 

[steadyon]

As a first step I'd suggest balancing the radiators (See FAQ's). Sounds as if there is insufficient heat being lost in the radiators, (flow v return temps.). The heat lost between flow and return at each radiator is lost in heating that room.

 

[lddex]

As a first step I'd suggest balancing the radiators (See FAQ's). Sounds as if there is insufficient heat being lost in the radiators, (flow v return temps.). The heat lost between flow and return at each radiator is lost in heating that room.

thanks. Should have said, when the new radiators were fitted - the guy said he had balanced them. I have to admit I took his word at face value. But none of the radiators seem to be hotter or colder than the others. But will try this.

 

[ShaunCorbs]

How is the nest fitted is it simple on off or open therm

 

[lddex]

How is the nest fitted is it simple on off or open therm

Not sure i get what you are asking. Its been wired into the boiler, so when it reaches set temperture it switches boiler off.

 

[SimonG]

Single pipe or two pipe system?
15mm radiator feeds or smaller?
Size of rooms? V Size of rads?

 

[lddex]

Single pipe or two pipe system?
15mm radiator feeds or smaller?
Size of rooms? V Size of rads?

How would i know what type of system it is. I think its just single pipe as one pipe goes in to radiator and then comes out the other side. the size of rooms are average size. Not overly big and the upstairs radiators have been sized accordingly. As for the pipes, its not micro bore , but i think one plumber said 12mm or 10?

 

[Gasmk1]

how long is the heating on for

 

[lddex]

how long is the heating on for

3 to 4 hours. And as stated, this will only increase the temperature by 2 or 3 degrees.

 

[centralheatking]

Its really quite simple. Switch your boiler on turn to full heat, then touch the flow side of your boiler it should get blistering hot. Then wait, maybe touch the odd rad to see how hot..TOP & BOTTOM return to boiler and check flow side then see if the return is warm, hot ..it should take 20 30 mins for the return to equal the return then the boiler should modulate.
If this does not happen report back...in the meantime get rid of the hive device it might only complicate things or even be the cause
centralheatking

 

[SimonG]

How would i know what type of system it is. I think its just single pipe as one pipe goes in to radiator and then comes out the other side. the size of rooms are average size. Not overly big and the upstairs radiators have been sized accordingly. As for the pipes, its not micro bore , but i think one plumber said 12mm or 10?

Not giving much info.
Sized accordingly how?

Maybe best to get a good heating engineer in.

 

[townfanjon]

If everything is sized correctly ( rads and boiler ) it should heat . What actual temp is the house reaching ? , is there any insulation in the loft space ? It maybe worth borrowing / hiring a thermal camera to see where you are loosing the heat .

 

[Burger]

Sounds like a balancing/circulation issue. Might be best to get an engineer in.

 

[gmartine]

Do the all the radiators have thermostats (TRVs)?

 

[doitmyself]

the boiler seems to be running flat out, judging by the gas flame on my smart meter.

I doubt if the meter is showing real-time consumption; my British Gas one doesn't, it updates every half hour. So all it is showing is the total consumption over the last half hour.

Does the boiler stay on all the time while the house is being heated (flame icon on and radiator icon flashing)? Or is the boiler cycling - on for a few minutes, off for a few minutes? If it is, it suggests that the boiler is producing more heat than the radiators can use.

What S codes are you getting (sequence and timing)? See para 5.2 of User Instructions.