My radiators only get 'luke warm' since combi boiler installed

[chrism_123]

Hi

I have recently had a combi boiler installed and prior to this I had the storage tank type. Since I had the combi installed the radiators only get luke warm and not hot like they used too. In order for the house to get to a comfortable temperature of 21C, I have to have the thermostat on 30C for at least 4 hours in this cold weather and the dial on the boiler set at number 6.

On my old setup the radiators would get hot very quickly and within 30 minutes the house would be at a comfortable temperature whereas now it takes hours!

Any advice? Are combi boilers known for not being as effective?

Thanks!

Chris

 

[Whn1]

No, should be as effective as long as you don't have 1000 radiators.

How many rads do you have, what boiler is it? Has the system been balanced/bled correctly?

 

[Danv44444]

What combi boiler have you got?

 

[lame plumber]

a well installed combi is as good at heating rads as any other boiler. did the installer flush the rads thro, balance the system to its optimum is what you should be asking.

 

[chrism_123]

Thanks for the quick replies. It is a Worcester boiler and I live in a 3 bedroom house which has 7 radiators. The water pressure dial is at 2.

I live in a council owned house and I suspect the guys who did it did not do a good job. Sorry I know absolutely know nothing about boilers...is there any way I can check whether it has been balanced/bled correctly myself?

 

[plumber0808]

Any chance they have fitted thermostatic radiator valves and are all set low?

 

[erpkid]

I would imagine that your combi has been over specified to give you good water flow. In theory then the CH performance should be very good as boiler is usually over powered for the rads available It is very cold at the moment but you should not be feeling the cold. Balanced is easy , are they all equally cool /hot all around at full bore. Bled, are they cooler at the top than the bottom. If so the bleed each and top up as the gas is purged. Let us know what you find.

 

[chrism_123]

They did fit thermostatic valves to the radiators which made them even colder! I called them out and they took them off saying it will make them warmer and it has - but not by much.

In terms of water flow - water comes out of the hot tap very slowly. It used to come out very fast under the old system and fill the sink very quickly but now it takes a good minute or so to fill up. The cold water still comes out very fast though.

The radiators are all equally warm and not cooler at the top than the bottom. I have bled them.

Chris

 

[Whn1]

They've ruined everything!

 

[chrism_123]

Wish they bought the tank back - the water and heating was so hot!

 

[Whn1]

There's a major problem there. Flow rate of the hot water should be near equal to the cold main. Is there a heating thermostat that you've forgotten? Taking the trv heads off should not be necessary! What was their excuse for these things?

 

[chrism_123]

Hmmm I dont know but they said there is nothing wrong with it. The heating thermostat is on 30C.

They also installed a shower and the water temperature fluctuates between cold and hot constantly even if there is no one else in the house. It is never stable. If you turn on the taps downstairs then the shower goes cold but I had this issue with the last system too. I asked them to fit a thermostatic bar shower mixer valve to help but they said no.

In order to take a shower with minimum fluctuation and comfortable temperature I have to turn the hot tap on as far as it goes (but still comes out slow) and turn the cold tap the tiniest of fractions (as it comes out very fast).

 

[plumber0808]

The installer must know what is wrong, I wouldn't fit trvs and then come back and take the heads off, terrible service. Gives the trade a bad name

 

[Whn1]

To be honest you're not going to get much help online because it could be anything, the problem you have needs to be rectified by the shoddy installers, make sure you check they are competent gas safe installers, it's your right to ask.

 

[dancinplumba]

To be honest you're not going to get much help online because it could be anything, the problem you have needs to be rectified by the shoddy installers, make sure you check they are competent gas safe installers, it's your right to ask.

doesnt make them good heating installers tho

 

[chrism_123]

We rent the house from the council so we have to call them for any maintenance and they always send out the same people. They come out and say everything is working fine so it is very frustrating. I will try and take a video tomorrow of the water coming out of the taps, the boiler, radiators and shower and stick it on youtube for you to see and give any comments.

 

[dancinplumba]

was the system flushed before they fit new boiler ? is there a filter on the return ? are boiler isolator valves fully open ?

 

[Whn1]

doesnt make them good heating installers tho

I agree but even though it's council I wouldn't put it past them sneaking dodgy fitters with no gas safe at all.

 

[dancinplumba]

We rent the house from the council so we have to call them for any maintenance and they always send out the same people. They come out and say everything is working fine so it is very frustrating. I will try and take a video tomorrow of the water coming out of the taps, the boiler, radiators and shower and stick it on youtube for you to see and give any comments.

get someone from council to be there at same time as installers

 

[Danv44444]

There's a major problem there. Flow rate of the hot water should be near equal to the cold main. Is there a heating thermostat that you've forgotten? Taking the trv heads off should not be necessary! What was their excuse for these things?

The flo rate of the hot water will be nowhere nefarious equal to the cold main. I suspect the have fitted a 25si or even a junior which on has a hot flow rate of about 9 ltrs per minute

 

[Danv44444]

Near not nefarious!

 

[GasmanxxxR1]

Ch temp dial turned up on front of boiler?

 

[smtplumbing]

what kind of boiler did they fit, the other thing you could do is call the boiler company and say its not working and they will come and check it out etc tho it sounds like a install problem