Protherm 80e combi hot water problems
 

Please help

I have a protherm 80e combi boiler, less than 3 years old.
When running hot water, roughly every minute, the flames go out and
then immediately relight with an almighty explosion.
Very annoying when having a shower as it runs cold every minute

The central heating works fine and stays lit constantly.
I wonder if it might be something like the water flow sensor?

On Sun, 12 Sep 2004 02:13:55 -0700, charlie wrote:

Please help

I have a protherm 80e combi boiler, less than 3 years old.
When running hot water, roughly every minute, the flames go out and
then immediately relight with an almighty explosion.
Very annoying when having a shower as it runs cold every minute

The central heating works fine and stays lit constantly.
I wonder if it might be something like the water flow sensor?

I think you may have two problems here.
The first is that probably due to heat exchanger scaling the heat transfer
rate is limited and so the boiler can modulate down to the lowest power is
needs so it has to go out. (Might be many other causes but that is most
likely in any hard water area).

The second is some sort of explosive ignition problem.
Does the boielr make the smae sound when it first fires or only when it it
cycling on-off-on.?

If the gas supply was very under pressure you might just get both the
above symptoms form one cause. That would be worth eliminating from the
outset.


--
Ed Sirett - Property maintainer and registered gas fitter.
The FAQ for uk.diy is at www.diyfaq.org.uk
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Thanks for the reply,

I did think about the gas pressure it's LPG and the tank is only 25%
full, I've been waiting 2 weeks for calor to fill it up. I'll wait to
see if filling the tanks helps before trying anything else.

We are in a very hard water area, we were thinking of getting a water
softener, would this be OK with a combi boiler or would it reduce the
pressure to much?

the explosive ignition doesn't happen when it first ignites only when
it reignites

On 12 Sep 2004 14:07:22 -0700, "charlie" wrote:

Thanks for the reply,

I did think about the gas pressure it's LPG and the tank is only 25%
full, I've been waiting 2 weeks for calor to fill it up. I'll wait to
see if filling the tanks helps before trying anything else.

This seems pretty unlikely, because there is a regulator between the
tank and boiler to set the gas pressure to the required level.


We are in a very hard water area, we were thinking of getting a water
softener, would this be OK with a combi boiler or would it reduce the
pressure to much?

It won't reduce the static pressure at all.

It may have an impact on the flow, which may make the working pressure
that you feel a bit less. However you can get water softeners that
have high flow rates.

If your heat exchanger is scaled up as has been suggested, then it
would be prudent to get that resolved first.

A water softener will certainly prevent scaling and will save you
money on detergents and shampoos - will cover the cost of salt.

A less expensive alternative is to use a phosphate dosing unit like a
Combimate. This will prevent the scaling but not help with
detergent use.




the explosive ignition doesn't happen when it first ignites only when
it reignites

..andy

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