heating slowly

[qwertyjjj]

We have a spa, which is a Campeche model by system pools (about 5 years old).
It seems to be heating fairly slowly at present - any ideas on what could cause that?
It seems to take around 5 hours to only movefrom 24oC to 30oC. The standby mode heats the water once a day or as necessary in the program functions. When you turn on one of the pumps, bubbles, light, or CD, it is supposed to be in On mode and the heater functions ad hoc but it doesn't seem to heat any quicker than standby mode.

Edit: Currently takes about 10 hours to heat it up from 22 to 38 whether in On / normal heating mode.

[ejf The Spa Guy]

are you running power at 220 or 110., and your heater is working you say, how is your filter, how old is it.....

[qwertyjjj]

220V - it is a european model.
I don't think the filter has been replaced ever, the whole thing is a few years old.
How long should it take to heat about 10 degrees C?

[Spatech_tuo]

How long should it take to heat about 10 degrees C?

3 to 4 hrs I'd say

[ejf The Spa Guy]

yeh i would agree on that.

[qwertyjjj]

I guess I just figured it would be quicker.
So, 10-11 hrs to get it from 17 to 38 is about normal?
It just seems like if you ever want to use the hot tub you have to plan in advance and start it heating in the morning!

[ejf The Spa Guy]

well not really, depending on the customer. what they keep the tub set at,, i keep my personal tub set at 102 costs less to heat top keep at that temp, and if i drop my temp to say  90. my tub will not drop temp even fast enough to make that a concern....

[qwertyjjj]

how do you work out it costs less to keep at 102 then reheat from cold?
Surely only using it once a week, it's cheaper to heat from cold all the time (cold being about 17oC). On a hot day, the sun will heat it up to about 25 anyway and can start the heater soon after.