Gordo

No matter what we do, we can never get a really hot bath.

Boiler is a large combi Worcester Bosch thing that has just been serviced, it's on max for both central heating and hot water. taps in the kitchen etc scald your hands if you're not careful. Upstairs the bath tap gets just hot enough if you let it run for ages yet the shower next to it is fine.

any ideas? (before the missus has me carrying kettles up the stairs!)

Gordo

cletterridge

Run the bath slower - your boiler doesn't sound powerful enough for full flow.

Gordo

tried that - no difference (if anything, it's a bit variable). the biler is the size of a large washing machine, standing on the floor of the garage, allegedly the highest through-flow boiler on the market 6 years ago. the kitchen tap is more powerful and runs scalding.......

mattstant

in theory that should be impossible
as long as all other hot taps are off you should get the same temp and flow as the kitchen as long as the pipes are warm up which shouldnt be more than a minute????
are you sure its combi and are you sure the shower isnt an electrical one. ???
Even if the pipes are badly furred up you should still get the temp if not the flow.

<discliamer modeon > i am NOT a plumber but i have to specify heating systems through and done more than enough diy plumbing to be at least well informed <disclaimer mode off>

scooby nutter

Gordo
i think i know which boiler you have and its a good one
if you pull the front off, does it have a thing covered by some silver foil on the left hand side??(youl know if it has!)

if its what i'm thinking then is got a small cylinder built into the boiler.this heats up with hot water and the boiler keeps it at this temp.

think its called the Worcestor Heatslave??

Anyway ,your right they are the best combi boilers money can buy,we use worcestor all the time and never get any problems

How far away is the bath from the combi???

as someone else said try running the bath tap at a really slow pace,we have to do this with our worcestor,start filling the bath 20 mins before you want to use it!

??

Duncan corgi installer

TopBanana

Scooby nutter - what's so great about if it takes 20 mins to run a bath???

Confused

easyrider

Gordo-does the hot water come out hot fot the first min.then gradually cools off?
It does sound like the boiler is a Worcester Heatslave Hiflow,as what scoobynutter suggested.These boilers give a very good supply of hot water if set up properly,but if the flow is too high it will supply good hot water breifely but when the small cylinder inside runs out of that hot water the boiler cant heat it quick enough-thus being luke warm.This problem only usually rears its head with this boiler when the bath is being run-due to the amount of hot water needed and the type of taps(bath taps usually allow a higher flow-22mm supply).When you use the sink generally you dont use enough hot water to "empty" the tank + sink taps usually have a lower flow rate(15mm supply).As for the shower-showers tend to keep the flow down enough so the boiler can "keep up" with the demand.
If this is the case then you can either limit the flow by adjusting the mains inlet valve under the top cover(but they leak if you just look at them-let alone adjust them!!!),or you can just experiment with the flow by adjusting the bath tap.
Hope this helps
easy

Gordo

It's a Worcester Bosch Highflow 400 Series.

Will try running the bath really slowly - the internal heattank would explain why it can be sporadic and why the (non-electric!) shower next to it is fine. it's a long narrow house with th boiler and bath about as far apart as they can get, hence it takes the pipes a few mins to warm up.

I'll tell the growler to stop having baths.

cheers
Gordo

scooby nutter

Scooby nutter - what's so great about if it takes 20 mins to run a bath???

Confused

Well try filling the bath with a cheapo B+Q special
they cant heat the water fast enough,and most of em only require a 15mm gas supply!!!!!
you cant heat that much water with only the input of a 15mm gas supply(well you can if you like it luke warm).

Even the best combi's money can buy ie Worcestor or Vaillant take 10-15mins to fill a bath.you cant fill a bath with the hot tap fully oopen because the boiler cant heat it quick enough.