which gas combi replacement advice

[BobbyJoe]

Hi everyone,

Just a query about what size in KW gas combi boiler do I need for a top floor flat (3rd floor). I have a Vokera Easi heat plus (20kW) gas combi boiler and it does the job, the radiators never go as hot as the should for example there are ten dots on the heat dial but the radiators never get any hotter past the 5th dial and I don't know why?
Therefore I would like a better boiler with a DHW temperature which is displayed and also if possible with summer and winter dial and DHW flow control. Any advice on brand and size would be really appreciated thank you.

Stats on flat:

• Two bedroomed flat with high water pressure
• All water in flat is mains supply fed (kitchen and bathroom)
• 7 Radiators in flat ( 2 large radiators the rest medium sized)
• 1 bathroom with one thermostatic rainfall shower and one hand held shower
• Mixer taps on all water outlets
• 15mm pipes under sink
• 22mm Incoming mains water pipes in kitchen and bathroom airing cupboard
• Combi Boiler set up in kitchen with flue out the wall
• Bathroom is between 6 and 7 metres away from current boiler

Also what does the summer and winter dial function as on a gas combi boiler are they worth it and what does water flow function help with? Thanks again

 

[fowlerboi]

Your gas engineer will be better suited to help you with all the above including which brands he would prefer to fit considering he will be the one servicing it I would take his advice

 

[Timmy D]

Your gas engineer will be better suited to help you with all the above including which brands he would prefer to fit considering he will be the one servicing it I would take his advice

I agree. What ever combi you fit, will be big enough to cover the rads.

The combi should be sized to the mains flow rate. Make sure the flow rate is tested.

 

[Deleted member 120897]

This makes perfect sense, rads don’t get hot, so get one that performs better hot water delivery.

 

[BobbyJoe]

Thank you and what do you mean "Make sure the flow rate is tested." and how important is the flow rate what does it do?
What would happen if you got a combi gas boiler with the wrong flow rate? Thanks

 

[ShaunCorbs]

Ok let’s say you have an 7lpm incoming water flow rate

No point installing a 30kw combi that can give you 11lpm ish

 

[Gasmk1]

Ok let’s say you have an 7lpm incoming water flow rate

No point installing a 30kw combi that can give you 11lpm ish

Could alway install a booster pump Sean

 

[BobbyJoe]

Okay thank you. My taps give high pressure around 15 lpm but the boiler is a Vokera 24kw

 

[ShaunCorbs]

Do you have a bath / anything high flow ?

 

[BobbyJoe]

Bath has high flow/pressure as well as kitchen and basin taps. If I open the lever tapa fully water splashes out and soaks the floor in the kitchen and bathroom.

 

[ShaunCorbs]

Sounds like you need flow limiters fitting

 

[BobbyJoe]

Thanks, where do the flow limiters go? are they fitted on all faucet pipework's.

 

[ShaunCorbs]

They can of if you have a removable airrator/ outlet it can fit there

 

[Knappers]

If not you can get inline ones

 

[John-sjw]

When choosing a combi:
1) make sure it is 30Kw minimum. 24Kw struggle when it is below zero temps outside.
2) make sure it modulated to a low kW. The lowest is around 3 kW.
3) It has weather compensation.

I would advise the Intergas Xclusive. A quality combi. The weather compensation can be switched out to run at the boiler temp control, by having a simple switch on the wall (a light switch). Jut put the switch it in the wire to the outside sensor. When connected weather compensation automatically works, when broken by the switch it reverts to boiler control as normal.

 

[Knappers]

When choosing a combi:
1) make sure it is 30Kw minimum. 24Kw struggle when it is below zero temps outside.
2) make sure it modulated to a low kW. The lowest is around 3 kW.
3) It has weather compensation.

I would advise the Intergas Xclusive. A quality combi. The weather compensation can be switched out to run at the boiler temp control, by having a simple switch on the wall (a light switch). Jut put the switch it in the wire to the outside sensor. When connected weather compensation automatically works, when broken by the switch it reverts to boiler control as normal.

What a load of chuff!

 

[John-sjw]

What a load of chuff!

Di do not know much about this heating stuff do you?